Abalone shell is a particularly prized type of mother-of-pearl, as it displays iridescence unmatched by any other mollusk. Its bold blues and greens give way to a rainbow of flashes of other colors to create a truly unique display.
Achroite refers to the colorless variety of tourmaline. An elbaite tourmaline variety, these gems are very rare and especially prized by collectors.
Generally transparent or translucent green, green-black, or grey-green in color, actinolite is named after the Greek word for "ray" or "beam," aktinos, referring to its fibrous nature. Actinolite also goes by the nickname 'ray stone' and is fairly prevalent worldwide.
Adamite is one of the most well known minerals in the specimen market although the mineral itself is not terribly common. Cut gemstones are rare because of its low hardness (3.5), brittle tenacity, and distinct cleavage. It is highly prized for its aesthetic crystal shapes and formations, bright color (often a yellow to greenish-yellow), and stunning fluorescence (bright lime green).
Adularia is a variety of feldspar found in hydrothermal veins in mountainous areas, from one of which it derives its name: the Adular Mountains of Switzerland. It commonly forms as colorless to white, cream, pale yellow to pink, or reddish-brown, glassy, prismatic, twinned crystals. These transparent to colorless gems often display a white to blue sheen.
Aegirine is a member of the pyroxene group along with jadeite. It is typically dark green to dark brown in color and crystals comonly have distinct terminations. It is rarely seen as a faceted gemstone, probably because it appears to be almost black due to its high saturation. It has good hardness at 6, and moderate to strong dispersion, when its saturation does not obscure it.
Aeschynite is an uncommon, rare earth mineral that is seldom cut into a gemstone. Two varieties of aeschynite also contain the elements cesium and thorium which are radioactive. It is not recommended to store this mineral in inhabited areas or to have prolonged exposure to the body.
Named after the country, Afghanistan, where it was first discovered in a lapis lazuli mine in 1968, this rare and complex aluminosilicate forms blue crystals ranging from light aquamarine shades to saturated sapphire blue hues. The scarcity of gem-quality afghanite makes it a true collector's stone.
Agate is the banded form of chalcedony, a cryptocrystalline variety of quartz. Rather than a single crystal, it is composed of a myriad of miniature crystals that can only be seen with extreme magnification. Agate's name is derived from the site of its discovery, the river Achates (now Dirillo) in southwest Sicily. You will often find striking curved or angular banded patterns of color flowing within agate, which are caused by the presence of various minerals, often iron and manganese. One of the oldest known gemstones, agate is a favored material of lapidaries and artisans around the world.
Akoya pearls tend to be the most consistently round and near-round pearls, which makes them perfect for matching for multi-pearl jewelry. Akoyas are saltwater pearls prized for their roundness, luster, and color. They are small, ranging from 2 to 11 millimeters, as the akoya oyster is the smallest pearl-producing oyster. Akoya pearls are considered the "classic" pearl with their generally white to cream color, having rose or silver overtones.
Alabaster is a fine-grained massive form of gypsum. Alabaster ranges from white to yellow, pink, and brown. Due to its porosity it is often dyed. It has been used for centuries for statues, carvings, and other ornamental purposes. Treated alabaster is used as a marble simulant. Due to its extreme softness, it is ideal for fashioning into works of art.
Alexandrite is the rare color-change variety of the mineral chrysoberyl. Its rarity is a result of its unlikely chemical makeup. Alexandrite displays the color change phenomenon because trace amounts of Cr3+ has substituted for Al3+ in the crystal lattice. This substation rarely takes place making alexandrite extraordinarily coveted.
Blue-green specimens of microline are called amazon stone or amazonite, named for its supposed discovery location near the Amazon River. Amazonite that is used in jewelry is generally cut into cabochons. Gem-quality amazonite is found in the Ilmen and Ural Mountains of Russia, the Pikes Peak district of Colorado and in Minas Gerais, Brazil.
Amber is the ancient fossilized resin of trees that grew in forests millions of years ago. Over the eons, chemical and physical changes occurred, fossilizing the resin to produce what we know today as amber. Research indicates that amber ranges from about two million to 360 million years in age, although most gem quality amber is between 10 million and 50 million years old. Hardened resin that is significantly younger than amber, is known as copal. Although the age boundary that differentiates amber from copal is still debated, copal is considered to be less than 10 million years old, with a large proportion being significantly younger.
Amblygonite is quite possibly one of the most beautiful pastel colored gemstones that you may have never heard about. It belongs to a class of minerals known as phosphates and forms a solid-solution series with montebrasite. Industrial grade amblygonite isn't that rare; however, when it comes to facet grade material, it quickly moves up on the hard-to-find list. Colors for amblygonite include pale yellow to greenish yellow and various shades of green to blue. On rare occasions, pink to light purple specimens may be found. Colorless material also is available.
If you are fortunate enough to be born in February, amethyst is your birthstone. This wonderful member of the quartz family often forms large, six-sided crystals. It's usually quite clear and can be cut into almost every shape, which makes it ideal for jewelry. Because amethyst is a 7 on the Mohs scale of hardness, it's very wearable. Versatile amethyst offers a wide variety of shades, from reddish to violet-purple. If you prefer soft, subdued colors, you will truly enjoy the pastel lavenders of amethyst. Are you drawn to deeper, richer colors? Then you should consider some of the intense purple amethyst from Africa or South America.
Ametrine is a bi-color quartz variety that, as its name suggests, is a unique combination of amethyst and citrine within a single crystal. How the gem forms is still a bit of a mystery, but the differences in color are believed to be the result of the presence of iron in different states of oxidation from natural heating. Combining the golden sunburst of citrine with the violet sunset of amethyst, this naturally colored gem is commercially mined at a single source: the remote Anah mine in Bolivia and is shrouded in fascinating local legends and lore.
Ammolite is a gem that comes from the fossilized shell of an extinct, squid-like creature called an ammonite. Found in Canada, the iridescent shell of fossilized ammonites is available as ammonite fossils or in iridescent gems cut from the fossils under the trade name ammolite. Ammolite's iridescent play of color is what makes it so distinctive and attractive. Its iridescence occurs when the fossilized ammonite shell becomes mineralized. Unlike most gems, whose colors come from light absorption, ammolite's iridescent color is caused by interference with the light that gets trapped within stacked layers of thin platelets that make up the fossilized shell. Since the layer of ammolite is typically thin, most ammolite is made into doublets or triplets for use in jewelry. A doublet is a thin slice of shell that is typically covered by a durable material (often crystal, glass or plastic) that both protect the gem and maximize its presentation. Triplets are typically assembled by placing a thin slice of shell between two layers of more durable material that are attached with epoxy. While shades of green and red are usually seen, all spectral colors are possible.
Ammonites were marine animals that existed during the Jurassic and Cretaceous periods, and are related to modern-day octopi, squid and cuttlefish. The same event that wiped out dinosaurs was the end of this species, as well. On rare occasions, the ammonite fossilized shells became mineralized, exhibiting a striking iridescent play of color. Ammonite is typically found as fossil specimens or as iridescent gems cut from the fossils under the trade name Ammolite.
Andalusite, an aluminum silicate, derives its name from the southern Spanish province of Andalusia, long believed to be the site of its original discovery. The actual locale was a different province in Spain, El Cardoso de la Sierra, but the name Andalusite endured. Andalusite's color play has been compared to alexandrite, but this is technically incorrect, as andalusite is trichroic rather than color changing. Andalusite displays different colors in different directions and features all its colors at once, whereas color change gems like alexandrite only change color when exposed to different light sources.
Andesine-Labradorite is a beautiful crystalline gem that is a combination of two feldspar varieties: andesine and labradorite. Its name "andesine" refers to the Andes Mountains where andesine was first found and the name "labradorite" was derived from Labrador, Canada, where labradorite was first discovered. So why the hyphenated name? Chemically speaking, our material falls between andesine and labradorite, so we chose to hyphenate and use both terms to be more accurate and descriptive.
Angelite is the bluish gray nodular polished form of anhydrite that was discovered in Peru in 1987. It is used in jewelry, spheres, and carved eggs.
Anglesite gets its name from a deposit locality: Anglesey, an island in Wales. Anglesite forms several types of crystal habits: tabular, prismatic, pseudorhombohedral, or pyramidal. They resemble those of barite and celestite. Prized by collectors for its strong dispersion, anglesite is often colorless to white, grayish, yellow, green or blue.
Anhydrite’s name can be translated to “without water”. The only difference between anhydrite and gypsum is that it lacks water. It produces mineral specimens that have fan like sprays or cubes. It is used for soil treatments, construction materials, and used as the source of sulfur in sulfuric acid.
“Anyolite” comes from the from the Masai word anyoli, meaning "green." It is also known as ruby in zoisite. It is a translucent to opaque rock composed of ruby crystals, green zoisite and black or very dark green pargasite. It is used for cabochons and decorative objects. It was first discovered in 1954 at the Mundarara Mine, near Longido, Tanzania. It has also been found in the Muriatata Hills, Kilimanjaro Region, Tanzania.
Apatite is the name for a mineral group as well as the generic term for many phosphates, but gem-quality apatite is a special gemstone found in a beautiful variety of colors. Apatite's various colors are often due to the presence of rare earth elements or natural irradiation. Because of its wide color range, apatite has often been mistaken for many other gemstones, including topaz, tourmaline, and various beryl varieties. Particularly rare in sizes over one carat, apatite is a relatively soft gem and when used in jewelry manufacture, is often set into more protective mountings that capture light yet safely display its beauty. The long-established sources for gem-quality apatite are Brazil and Mexico, but more recent African discoveries have thrust it into the spotlight once again.
Apophyllite is divided into three distinct species, fluorapophyllite, hydroxyapophyllite and natroapophyllite, depending on their chemical composition. It was once considered to be a single mineral, so if chemical composition is not yet determined specimens will still be referred to as apophyllite. It is commonly found as glassy prismatic, blocky, or tabular white to grayish or light pastel crystals. The name apophyllite comes from the Greek word meaning "leafs off," referring to its tendency to flake when heated.
The birthstone for March, aquamarine is one of the most popular members of the beryl family, a sibling to emerald, morganite, bixbite, heliodor, and goshenite. The color ranges, depending on the relative concentrations and location of iron within the beryl crystal structure. Aquamarine's tranquil color and crystalline clarity capture the beauty of the sea, which is fitting as its name is formed from the Latin words "aqua," meaning water, and "mare," meaning sea. A favorite among gemstone lapidaries, rough aquamarine is relatively easy to fashion, so lapidaries often create imaginative aquamarine cuts and shapes.
Aragonite's name is derived from the location of Molina de Aragon, Spain, the province where it was first discovered. Aragonite occurs in Agrigento, Sicily, Italy, in the famous sulfur mines, as well as on Mount Vesuvius, Italy. Aragonite specimens are highly prized by mineral collectors for their wide variety of forms, which include twins and pseudomorphs (uncharacteristic crystal forms). As an added bonus, many specimens are fluorescent as well as phosphorescent, a rare occurrence among minerals.
Arsenopyrite is the most common arsenic mineral, once known as arsenical pyrites. Its color is silver-white to steel-gray on freshly broken surfaces. It yields a garlic odor when heated and the fumes can be toxic. It may tarnish to form an iridescent layer. Although it has a reputation for being poisonous to humans, complex arsenic compounds are used in the treatment of disease caused by microorganisms.
Astrophyllite is golden-yellow to dark brown and usually forms as bladed crystals radiating from a common center. It gets its name from the Greek astron, meaning "star," and phyllon, meaning "leaf." It may also be translated as "star sheets" because of the interwoven star shapes that crystals sometimes form, and because of its strange luster, which can be metallic or pearly. Although there are occurrences of astrophyllite around the world, some of the finest crystals come from remote mountainous regions in arctic northern Russia.
Aventurine is a form of quartz, distinguished by its translucent to opaque appearance and the presence of mineral inclusions that give a shimmering or glittery effect termed aventurescence. The phenomenon of aventurescence is caused by small leaf-like or plate-like inclusions, usually mica, distributed throughout the host material. Light striking the surface of these inclusions is reflected back to the viewer, creating an eye-catching sparkle. While customarily green in color, aventurine may also be found in colors ranging from blue, orange, white, yellow, reddish-brown to gray.
Axinite is an uncommon mineral that usually occurs in long, flat, axe-shaped crystals, a trait that makes it highly desirable to collectors who enjoy adding various crystal forms to their collections. Its strong trichroism only adds to its special appeal. As it is rotated, different colors are displayed, including rich cinnamon browns, violets, blues or greens.
Azurite is a copper carbonate mineral found in the oxidation zones of copper deposits and is considered a secondary ore of copper. Color ranges from light to dark blue, with medium to dark blue being more common. The intensity of its hues is what makes azurite a popular collector's stone. Azurite is commonly found in conjunction with malachite, a green copper carbonate mineral into which it slowly morphs. A mix of the two minerals is known as azurmalachite. Azurite is soft (3.5 on the Mohs scale) and opaque. When used in jewelry, it is usually seen in the form of cabochons or beads.
This trade name refers to a natural mixture of azurite and malachite that is often banded and can be used as both a gemstone or in decorative items. The bold greens and blues beautifully intertwine to form unique mineral specimens or gems, each piece always one-of-a-kind.
This mineral is most often white or colorless but can form in an array of colors. It is prized among collectors for its various crystal forms and habits. Barite can be easily identified by its weightiness, as it is much heavier than most similar minerals.
A rare gem, bastnaesite is named after the Swedish locality where it was originally discovered in 1841, the Bastnas mines. Color can range from honey yellow to reddish brown and crystals vary from transparent to translucent in appearance. Valued by industry as a source of rare-earth elements, bastnaesite is rare, but has been found in small quantities throughout the world. It is difficult to cut because it is a relatively soft mineral, however, its high refractive index, combined with its rarity, make it an exciting gem to own.
Bayong is a hardwood tree from the Philippines. The wood is used to make beads and jewelry. The leaves can be woven into purses and baskets.
Benitoite is a single-source gemstone, meaning that so far, it has been found in only one place on Earth: San Benito County, California. Benitoite grows in relatively small crystals, only a portion of which are gem quality--further increasing the rarity and value of this unique gemstone. Gem-quality benitoite over one carat is incredibly difficult to come by. California's state gemstone, benitoite is especially prized by collectors for its strong dispersion, which rivals that of diamond in lighter material.
The name beryl is derived from the ancient Greek term for the same gem, beryllos; also the etymology for the element beryllium that is part of its chemistry. Some scholars believe the word beryl is related to the ancient trading city of Belur or perhaps has ancient Indian origins (being derived from the old Hindi word velurya or the Sanskrit word vaidurya). Varieties include emerald, bixbite (red beryl), morganite, aquamarine, heliodor (golden beryl) and goshenite.
Named for its beryllium content, beryllonite is a colorless to white or pale yellowish crystal. It is usually transparent with a vitreous to pearly luster, and is often heavily included. This rare gem is found in only a few places around the world, notably in Maine, USA.
Bismuth is rarely found naturally in its elemental form (even less commonly than platinum), but lab-grown crystals are gaining in popularity for their unique geometric formations (hopper crystals) and phenomenal iridescence. Bismuth is a silver-white metal, but an oxide layer forms immediately when crystals make contact with air. This produces an array of colors similar to that of a soap bubble or oil on water. The different colors are dependent upon the thickness of the oxide layer, which determines how light is reflected off of the surface creating a striking rainbow effect.
Red beryl or bixbite is the slightly purplish red to orange-red variety of beryl. It was discovered in 1904 in the Thomas Range of Utah by Maynard Bixby. Gem quality red beryl was found in 1958 in the Wah Wah Mountains of Beaver Creek, Utah. The material is typically included and faceted stones above 1ct are rare. Synthetic red beryl was produced in a Russian lab starting in the 1990’s but it is not known to be currently in production.
Black opal is the rarest and most valuable variety of opal. Black opal displays “play of color” and has a black, gray, dark green, dark blue, or blackish brown body color. Most black opal comes from Lightning Ridge and Mintabie, Australia, but it can also be found in Java, Virgin Valley, Nevada, and Wello, Ethiopia.
Blister pearls are large pearls that have intergrown with mollusks or freshwater mussels and are integrated with the shell. Solid “blister” pearls are akin to mabé pearls, but they are natural and not assembled. They are known to have a high luster and are more durable than mabé pearls. They are typically rounded or irregular in shape and have been known reach 2 cm in size. They are more often found in in larger Pinctadas molluscs. They are called “puku” in the Cook Islands. They are also found in freshwater river mussels in North America. The freshwater blisters pearls are often found in mussels with distorted shells and are come in irregular, round or button shapes. Snail blisters are created when small snails or mollusks invade the mussel shell. Blisters pearls have also been found in “Lion’s Paw Pearls” in Laguna Ojo de Liebre in Baja California, Mexico, and Conch pearls in the Caribbean.
Bloodstone is green jasper dotted with bright red spots of iron oxide. The green color is caused by small particles of chlorite, a silicate mineral or hornblende needles interspersed throughout the host material. Its distinctive reddish spots are caused by the presence of iron oxides.
Since prehistoric times, people have used animal bones for ornamentation. Their relative softness lends to beautiful carvings for both detailed figurines and jewelry, often as beads. Cultures without access to ivory often used bone for similar purposes.
Known for its lively, flaming color displays, boulder opal is in high demand by collectors and jewelry designers. As opposed to cut opal gems, boulder opal features small opal veins running through its matrix. The precious opal's rainbow of colors make a dramatic contrast to the rich earthy reds and browns of the host rock, creating a one-of-a-kind display.
Although this phosphate mineral has a hardness of 5.5, brazilianite is fragile due to its perfect cleavage and brittle nature. Most brazilianite is chartreuse to pale yellow and forms in granitic pegmatites associated with tourmaline and apatite.
Bronzite is an iron-bearing variety of enstatite distinguished by its green-brown color and bronze-like sub-metallic luster with fibrous inclusions. Enstatite is a silicate and a member of the pyroxene group. Appreciated for its sheen, bronzite is sometimes polished to make small ornamental objects.
Named in honor of its discoverer, Anastasio Bustamante, bustamite is a member of the wollastonite group. Similar to rhodonite in appearance, it is usually found as a massive transparent pink material that may be cut into cabochons or carved into figurines.
Bytownite is a rare variety of feldspar named for deposits found in Bytown, Canada (now Ottawa). Some forms of this gem distinctly resemble the gemstone andalusite, another member of the feldspar group.
Named for its calcium content, calcite is one of Earth's more abundant minerals-- you've probably seen it many times and not known exactly what it was. It is found in marble and limestone, as well as other rocks used in industrial settings. Gem-quality calcite, however, takes on a quite different look. You may have seen colorless calcite crystals used as examples for double refraction, but it also forms as white, gray, yellow, pink and green gems. Material is often faceted or polished en cabochon, or carved into ornamental objects.
Also called "rainbow calsilica," this is a man-made material that displays vibrant layers of bold color. It consists of a mixture of calcite, plastic and coloring pigments. This unique stone is often used in jewelry and carvings to show off its distinctive coloration.
Capiz Shells come from the province of Capiz and the island of Samal in the Philippines. The shells are often called windowpane oysters because they have been harvested for thousands of years for use as windowpanes. Capiz shells are also used today in chandeliers, lampshades, decorative objects, clothing decoration and jewelry. The shells are translucent in their natural state and turn opaque when heated. When shells are heated for longer periods of time, they turn a smoky brown color. Shells are also dyed fashionable colors.
Carnelian is a translucent orange to red variety of chalcedony. Uniformly colored cryptocrystalline quartz, its red tints are caused by traces of iron oxide. The name is derived from the Latin world for flesh, carnis, due to its orangey red color. Carnelian has been appreciated since antiquity, and is one of the first known materials ever to be used as a gemstone.
The name Cassiterite is derived from the Greek word kassiteros, meaning “tin.” Cassiterite is best known as a tin ore. Gemstones fashioned from cassiterite are quite striking. This is due in part to its high dispersion, which is nearly double that of diamond. It is especially prized by gemologists and mineralogists for its unusual, twinned crystal formations. Durable and dense, it has been used as the chief ore of tin throughout the ages. Cassiterite often exists in placer stream deposits where it collects as rounded, water-worn pebbles.
Very distinctive in appearance, cavansite is a rare, not to mention strikingly beautiful, blue mineral. Its name is derived from its composition: calcium, vanadium and silicon. Only discovered in the 1960's in Oregon, cavansite is highly sought after by mineral collectors across the globe. Found in a scant few locales, cavansite sources include Brazil, India, New Zealand and Oregon USA. It is renowned for its stunning deep blue hues that are sometimes vivid enough to be described as "electric blue."
Celestite, also called celestine, is named for the Latin coelestis, meaning "heavenly," in reference to its often sky-blue color. This unique gem often forms beautiful transparent to blue tabular crystals, but it can also be colorless, white, light red, green, blue or brown.
Named for the Latin word cerussa, meaning "white lead," cerussite is a lead carbonate mineral. It forms in several different crystal habits when carbonated water interacts with other lead minerals. Prized by mineral collectors for its twinned V-shape crystals that are transparent to translucent and are colorless to white, gray, brownish or greenish. Although too soft for jewelry, cerussite is occasionally faceted for collectors; however, it presents challenges to lapidaries due to its soft, brittle nature.
Chalcedony is a broad gemstone family of many varieties of cryptocrystalline quartz gemstones. Chalcedony usually has a waxy luster and appears in a great variety of colors including blue, white, buff, tan, green, red, gray, black, yellow or brown. Different colored varieties of chalcedony have individual names including agate (banded), bloodstone (green with red spots), chrysoprase (apple green), carnelian (orange to red), flint (dull gray to black), jasper (spotted red, yellow, brown or green) and sard (light to dark brown).
Named for the Greek khalkos meaning "copper," and "pyrite," chalcopyrite is a major ore of copper. It has a metallic luster, resembling gold. Specimens are often collected and are found in Colorado, Arizona in the USA, as well as England, Tasmania, Germany, Canada, Spain, Japan and China.
Charoite offers an intriguing, mystical array of patterns that are both eye-catching and mesmerizing. The patterns often exhibit a combination of swirls, veins and spots that give each piece a unique and magical appearance. The name Charoite is used to describe both a mineral and an attractive gem material primarily composed of charoite. The gem material comes from the remote, mountainous region of the Sakha Republic of Russia, which remains its only known source.
Chondrodite, named for the Greek word for grain, "chondros," is a member of the humite group of minerals. Its gemmy hues range from red to yellow to orange, with the latter resembling the color of spessartite garnet. It can be found in several places including New York, Burma, Tanzania, and Afghanistan.
Chrome diopside has several origins, but most of the finest material, and the only commercially viable deposit, is in the Republic of Sakha in Siberia, Russia. As you can imagine, production of this Siberian treasure is sporadic due to extreme winters that last more than eight months. The vivid greens of chrome diopside are a welcome alternative to rare and pricey emerald or tsavorite garnet, but it has yet to gain mainstream recognition due to its limited availability. Minor sources of chrome diopside include Australia, Austria, Canada, Finland, Italy, Madagascar, South Africa, and the United States.
First discovered in Tanzania in the 1960's, chrome tourmaline is a fairly new addition to the vast tourmaline family. A true collector's gem, chrome tourmaline exhibits bright green color that resembles, and even rivals, that of the finest emeralds. While it is a type of green tourmaline, not all green tourmalines contain chromium and can be called chrome tourmaline. True chrome tourmaline is more highly prized, as it is a more rare occurrence for chromium to be a coloring agent, which often results in a much brighter and richer green color.
Chrysoberyl is the name of a mineral as well as three different gem varieties two of which are widely accepted as some of the most rare and valuable of all phenomenal gems. The gem commonly known as chrysoberyl is a yellowish-green, brownish-yellow, or colorless transparent to translucent mineral that is usually faceted into gems and generally considered a collector's stone. While not often set in jewelry, its characteristics make it ideal for such use. When chrysoberyl displays color-change properties, it is known as alexandrite, and when it exhibits chatoyancy, it is known as cat's eye chrysoberyl.
Chrysocolla, derived from the Greek chrysos meaning "gold," is a copper mineral. Crystals are very rarely seen, but it is frequently intergrown with other minerals such as quartz or opal. This results in a harder, more resilient gemstone, as pure chrysocolla is soft and fragile. Its copper content is responsible for chrysocolla's range of bright green to blue hues.
One of the most coveted varieties of chalcedony quartz, chrysoprase is prized for its apple green color and rarity. Chrysoprase's name comes from the Greek words chrysos meaning “gold,” and prason meaning “leek,” due to its color similarities with the vegetable.
Named from Arabic and Persian words for "dragon's blood," cinnabar comes in a remarkable brick-red color and has been used as a pigment in China as far back as prehistoric times. Gem crystals are rare collector's pieces, but opaque material is often cut into cabochons. Natural cinnabar is a major mercury ore and is not used in jewelry making, but a resin product that closely resembles it, is used in jewelry. The red color is so fresh and vibrant that, in China, many people call it "China Red."
Citrine is one of the most popular gemstones in the quartz group. Prized for its excellent transparency, citrine is one of November's birthstones. Naturally, it occurs in close proximity to amethyst and is found in beautiful golden, mandarin orange and madeira red hues. It's possible that quartz crystals that grew naturally as amethyst or smoky quartz were turned into citrine by natural heat from nearby magma activity. Today, many of the citrines on the market are actually heated amethyst or smoky quartz.
A relatively new addition to the world of gems, clinohumite was first discovered in 1876 within stones erupted from Mount Vesuvius. Only recently have gem-quality pieces been found in locales including Tajikistan's Pamir Mountains. Clinohumite's coloring typically ranges from bright yellow to deep orange to red, but a few brown specimens have been found.
Named for its resemblance to zoisite, clinozoisite is a colorless to pale grayish-yellow to green-colored mineral ideal for faceting. This gem was first discovered in Austria 1896, but there are many locations world wide where specimens have been found.
Cloisonné is an enameling or inlay technique used to decorate jewelry or other metallic objects. The enamel or gemstones are applied to create patterns or geometric designs. The colored material is placed in compartments or in between raised strips of metal. The earliest examples of the technique can be found in Egypt, Mycenae, and Mesopotamia and date to around 1200 to 1101 BC. Cloisonné has been used as a decorative technique by many cultures around the globe.
Cobaltocalcite refers to a stunning pink-red to slightly purplish-red cobalt-rich calcite mineral. Another name for this stone is cobaltoan calcite. Crystals often form as drusy masses and when faceted, gems are rarely seen in sizes greater than 2 carats.
A major source of boron, colemanite was discovered in 1884 and named for the owner of the California mine where it was first found, William Tell Coleman. The color of this stone ranges from colorless to white to grey, sometimes yellowish. Specimens are very sensitive to heat. The short, prismatic crystals are often sought after by collectors. Colemanite is rarely seen in the form of gemstones as it presents a challenge to lapidaries because crystals are soft, brittle and have perfect cleavage.
A conch is a marine gastropod or, more simply, a large sea snail. Conchs are valued for their meat, shell, and non-nacreous pearls. Conch pearls are formed by concentric layers of fibrous calcium. This layering often produces a much-desired flame structure, which is characteristic of conch pearls. Because they are a calcareous concretion, the pearls have a porcelain finish and luster, very similar to the interior of the conch shell. Conch pearls are usually found as a by-product as fishermen clean their catch for conch meat. The gems are usually baroque or oval and generally a salmon-colored orange pink.
Copal can be thought of as 'baby amber.' Like its much older counterpart, it is a hardened resin that originated as tree sap. Copal is similar in both appearance and chemistry to amber. Opinions vary from source to source as to when copal becomes amber, but the general consensus is that organic resin younger than 10 million years old is copal, while anything older is amber. As amber can be as old as 360 million years old, copal is substantially younger.
Many minerals are copper ores, meaning they contain copper that could actually be extracted. Copper weathering is often involved in the unique coloration of specimens. Popular minerals that fall in this category include azurite, malachite and chrysocolla.
Coquina is a poorly cemented limestone that is composed of shells and remains of fossilized invertebrates like brachiopods, mollusks, and trilobites. It gets its name from the Spanish word for shellfish.
Coral has been prized throughout history for its natural beauty. Like pearl, coral is also an biogenic gem consisting of more than 90% calcium carbonate. All coral consists of the remains of skeleton-like support structures that were built by colonies of very small marine animals, known as coral polyps. Proteinaceous coral differs from calcareous coral because it is made up of strong keratin proteins.
Cortez pearls come from the Gulf of California also known as the “Sea of Cortez”. The pearls are harvested from the Panamic Black-Lipped Oyster (Pinctada mazatlanica) and the Rainbow-Lipped mollusk (Pteria sterna). Only about 4,000 pearls harvested each year meet the industry’s quality standards to be sold on the gem market. The pearls have a beautiful luster due to their exceptional nacre thickness. The pearls can come in silver, gray, gold, green, blue, violet, purple, and black with pink, violet, blue and green overtones. The pearls average 6.5 to 8.5mm but some 14mm pearls are known.
Corundum is a mineral species best known for its two popular gemstone varieties, sapphire and ruby. All colors of corundum except red are known as sapphire. The term sapphire, when used without any modifiers, refers to only the blue variety of corundum. Red stones are known as ruby. Material that are not gemstones are simply known by the name corundum.
Creedite was discovered in the Colorado Fluorspar Co. Mine in 1916. The mine is located in the Creede Quadrangle, Mineral County, Colorado and this was the inspiration for its name. It comes in colorless, orange, purple, violet, and white prismatic crystals that sometime radiate from the base.
Crocoite was once called “Red Lead Ore” due to its lead content. The name Crocoite comes from "crocon" the Greek word saffron. Specimens are bright yellow, orange, or dark red and typically form as long prismatic crystals. Some of the best examples come from Australia.
Lead glass or crystal glass is frequently called crystal. George Ravenscroft patented a process for making lead crystal around 1673 in London. The addition of barium oxide, lead oxide, potassium oxide or zinc oxide, to glass improves clarity, raises the refractive index, and increases dispersion. Famous crystal manufacturing houses are located in Austria, France, Ireland, and Sweden.
Cubic Zirconia (abbreviated CZ) is the best-known man-made diamond simulant. A simulant is any material, natural or created by man, which imitates the appearance of a natural gem whereas a synthetic gem is man-made but must have a natural counterpart that duplicates the chemical, optical, and physical properties of the natural gem. While it's often touted as the most popular diamond simulant, cubic zirconia is also a synthetic gem. Natural crystals of cubic zirconia have only been found as inclusions in zircon.
Cuprite is a secondary mineral formed by the oxidation of copper sulfide veins. It is commonly found with native copper and malachite, and forms as both transparent red and lustrous, submetallic crystals. Transparent crystals may be faceted if large enough, but specimens are also commonly displayed as a glittering bed of crystals.
Danalite is a very rare brown, yellow to pink-red colored mineral named for the American mineralogist James Dwight Dana in 1866. Danalite has a limited number of global sources, including the New England states of Massachusetts, Rhode Island and Delaware.
In 1839 American mineralogist Charles Upham Shephard discovered a clear, bright, colorless gemstone in Danbury, Connecticut, and named it danburite after the location. Unfortunately for danburite, it was discovered at a time when colored gemstones were heavily promoted and highly desired. This colorless find, therefore, didn't create much excitement at that time. Danburite, which belongs to a class of minerals known as silicates, remained relatively unknown for years, but is steadily growing in popularity today.
Datolite is a phyllo-borosilicate commonly forming as nodules in igneous rocks. Facet-grade material rarely yields gems larger than 10 carats, with most being significantly smaller. Colorless, transparent datolite gems can be found in several locations worldwide, but many come from Connecticut, Massachusetts, New Jersey, and Virginia. Copper-stained, opaque nodules from Michigan are typically fashioned into cabochons.
Demantoid garnet is one of the most desirable of all colored gemstones and extremely rare. A color variety of andradite garnet, the name demantoid originates from the old German word demant meaning "diamond-like," because of a luster and dispersion that yields a fire even higher than diamonds.
This type of opal features dendrites, which are fern-like inclusions of iron, manganese, or other metallic oxides that create bold patterns within the gem. Typically, dendritic opals are cut into slices to best exhibit nature's artwork. As you might guess, these pieces are one-of-a-kind, as no two dendritic patterns are the same. Usually these opals are white, yellow, blue, green, or pink and show black inclusions well.
Ahh, diamonds. Everyone knows what diamonds are, but most might not realize what they once were: chunks of dark, nondescript carbon similar to charcoal, roasting and rumbling around deep within the earth. Fortunately, through eruptions and other harsh works of Mother Nature, diamonds eventually find their way to the surface for man to find, cut, polish, and enjoy. Talk about an ugly duckling turning into a swan! Named from the Greek word adamas, meaning "unconquerable," diamonds are renowned for their impeccable hardness and stellar brilliance.
Diaspore is beautiful and exotic in a soft, subtle manner. It is also one of the lesser known of the color-change gemstones. Some of the finest examples of gem quality diaspore are found in Turkey's Anatolian Mountains, but it can be found in numerous places around the globe. A rising star in fine jewelry, it's easy to fall in love with its sparklingly brilliant, tranquil earthy colors.
Diopside can be colorless but it most often a bottle green, brownish green or light green. Bright green diopside is commonly known as chrome diopside because of its chromium content. A rare blue variety known as violan may be found in Italy.
Dioptase is a bright emerald-green or blue-green gemstone noted for the visibility of internal cleavage planes. The transparent to translucent dioptase gemstone is uncommon and generally found in desert regions. Rivaling the beauty of emerald, dioptase is typically sold as specimens and gemstones are rarely seen, especially in sizes over 1 carat.
Dolomite is a white to brownish and sometimes pink-colored mineral named for French mineralogist Dodat Gratet de Dolomieu in 1791. Specimens are usually found in crystal clusters and have been known to be large in size. Transparent dolomite gems can be difficult to find due to their cleavage and low hardness value. They are usually preferred as a collector’s stone.
The word "drusy," is a mineralogical term used as both a noun and an adjective. The noun refers to a mineral coating of thin layers of tiny, tightly-packed crystals that resemble glittering sugar granules. The adjective refers to any such granulated crystal layers in reference to a given mineral; in this case, drusy quartz. Drusy quartz is usually found in the inside of geodes. When fashioned into loose gemstones and jewelry, it is often coated with a metallic color to capitalize on the glittering natural crystal facets and give it a more bold appearance.
A mineral that often forms as an inclusion in quartz, dumortierite is usually fashioned as cabochons or beads for jewelry. While prized for its deep violet to blue colors, it may also be found in shades of pink, gray and brown. Named for French paleontologist Eugene Dumortier, dumortierite is an exotic gem that is durable, untreated, and rare.
Edenite is named for Edenville, New York which is the first known location where it was discovered. Specimens can be green, gray, brown, and white, and well-formed crystals are commonly found.
The rich greens of Eilat stone come from it being a unique combination of various copper-bearing minerals including chrysocolla, malachite, azurite, and turquoise. Eilat stone is the national stone of Israel. It is known as King Solomon stone, as it comes from what is storied to be King Solomon's mines in the Timna Valley of Israel.
The tourmaline family consists of at least 14 distinct minerals, but the elbaite variety accounts for nearly all gem-quality tourmaline. It was named for the colored and colorless tourmalines found on the picturesque island of Elba off the western coast of Italy. Although best known in shades of green and red, elbaite can also be blue, purple, yellow, or colorless. Notable varieties of elbaite include rubellite, green tourmaline, indicolite, watermelon tourmaline, and Paraiba tourmaline.
Few gemstones command as much desire and passion as emerald. Since antiquity, emerald's rich "green fire" has symbolized eternal spring and immortality. Long shrouded in myth and lore, emerald has reigned as the supreme green gem with no indication that its position will ever change. The favorite of Cleopatra, Spanish Conquistadors, and Hollywood’s Red Carpet, wars have waged over this treasured stone. In the 1st century AD, Roman historian Pliny the Elder wrote that "nothing greens greener" than emerald, a sentiment still relevant today, as it remains one of the most sought-after gems on the market. The beautiful green hues of this beryl variety, combined with its rarity, make it one of the world's most valuable gemstones.
Enstatite is a common silicate mineral in the pyroxene family. Enstatite’s normal color range includes shades of green to brownish green, yellow green, yellow to brown, orange to reddish brown, and colorless. This gem has been identified in meteorites, and it is believed to be one of the early stages of crystalline silicate formation in space.
Enstatite normal color range includes shades of green to brownish green, yellow green, yellow to brown, orange to reddish brown, and rarely colorless. This gem has been identified in meteorites, and is believed to be one of the early stages of crystalline silicate formation in space.
A pearly transparent to nearly opaque gemstone, Epidote often has a yellowish-green or green "pistachio" color. Faceted stones may appear black due to the dark nature of the colors. Epidote specimens are often appreciated for their dramatic crystal displays featuring long and slender prismatic crystals. Epidote also forms needle-like inclusions in Prehnite and quartz.
Although euclase can resemble beryl in its appearance, that is where the comparison ends. Unlike beryl, euclase contains water, has a monoclinic crystal system, and a higher specific gravity. Only occasionally do its well-formed crystals have sufficient clarity to be cut as gemstones. Crystals are commonly prismatic, can be long or short, and are striated. Because of their rarity, gems with good clarity command premium prices. Most material is colorless to pale blue or pale green, but colors can range from blue to blue-green, green, yellow, white, colorless, and, rarely, purple.
Discovered 1819 in Greenland, this gemstone is usually found in massive forms in host rocks. Eudialyte is an extremely rare and complex mineral that occurs in red-violets, pinks, blues, yellows and browns. Well-formed crystals are rare, and opaque material is often fashioned in cabochons.
The feldspar group is made up of many closely related mineral species. Feldspar minerals are some of the most abundant minerals within the Earth’s crust and are a common component of rocks. Species that are rich in potassium (K) are called potassium feldspars. Orthoclase, Microcline (Amazonite), and Sanidine are potassium feldspars. Feldspars rich in sodium (Na) or calcium (Ca) are plagioclase feldspars. Albite, Oligoclase, Andesine, Labradorite, Bytownite, and Anorthite are plagioclase feldspars. The crystal structures of potassium and plagioclase feldspar are so similar that they frequently occur together, as alternating bands, within the same material. Feldspars can be triclinic or monoclinic depending on variety.
Ferberite is an iron-rich mineral commonly seen as a black to dark gray prism-shape specimens with metallic luster. At times it can exhibit weak magnetism and should not be confused with hematite.
Ferroaxinite is the iron rich variety of axinite. Crystals are flat and resemble an axe head. It can be found in granite and other igneous rocks. It can be pyroelectric and piezoelectric.
Unique and mysterious, fire opals are appropriately named for their fiery cherry, sunburst yellow, and deep tangerine coloration. Unlike precious opal, fire opal does not usually display play of color; specimens that do are highly valuable. Mexico is a primary source of fire opal, where it was treasured by the Aztecs who called it "gem of the bird of paradise."
A plentiful, affordable, and colorful gem, many consider fluorite one of the most popular collector's stones worldwide. Fluorite often has excellent clarity and crosses the entire color spectrum. One of the most famous fluorescent minerals, fluorite often requires no type of treatment to enhance its appearance. Also prized for its color-change and distinctive multi-color banded varieties, this beautiful stone has so many appealing features, it's no wonder that Roman historian Pliny the Elder named fluorite his "most precious substance."
Forsterite is a colorless to greenish transparent member of the olivine mineral family, which also includes peridot. Forsterite has a heavy magnesium chemical composition and large crystals are not common, but they are highly sought after by collectors.
Fossils are the preserved remains or traces of long dead algae, animals, and plants. The oldest known fossils are 3-billion-year-old ancient algae. The word fossil comes from the Latin word fossus which translates to “having been dug up”. For a fossil to form, an organism, or the trace of that organism, must be buried by sediment. Over long periods of time the remains will become preserved when the surrounding rocks alter the chemical and mineral composition of the remains.
Coral is the calcareous skeleton of marine animals known as coral polyps. The oldest known corals date back to 500 million years ago. In fossil coral the aragonite of the original structure is replaced by calcite or agate. The fossilization process preserves the ancient corals and makes very attractive cabochons that can be used in jewelry.
Although freshwater pearl cultivation originated in Japan, China is now the world's major producer of freshwater pearls. The humble freshwater mussel, while not as widely celebrated as its cousin the oyster, is capable of producing high-quality pearls. Generally speaking, freshwater pearls do not have the luster and shine of saltwater pearls, but they do form in a variety of shapes and colors and are typically sold at lower prices.
This sparkling green mica is a variety of muscovite colored by chromium, the same element that colors emerald and ruby. In fact, the most popular variety is called ruby fuchsite due to the ruby inclusions embedded in the fuchsite crystals.
Gabbro is a rock that is made up of calcium rich plagioclase feldspar and pyroxene, usually augite. Gabbro is found in a variety of locations and has even been discovered on the moon. The colors of gabbro are typically dark gray to black with a medium to coarse texture. It is a favored medium in architectural designs.
Ranging from green to brownish black in color, gadolinite is a mineral that counts Russia as one of its primary sources. Interestingly, gadolinite is prized for the two rare earth elements it contains: yttrium and cerium.
Galena is found as attractive mineral specimens. Its cubic structure with perfect 90-degree cleavage planes along with its bright silver like metallic luster is eye catching. Most galena is mined as a lead ore. Argentiferous Galena is sought after for its silver content and greatly increases its ore value.
Though they all have the same crystal structure (cubic, like diamond and spinel), garnet is an entire group of minerals that vary in their chemical composition, resulting in a variety of gems featuring different colors and properties. Though some varieties of red garnet are common and found on nearly every continent on Earth, other garnets like orange spessartite, green demantoid and tsavorite, are much less abundant. There are more than 20 garnet species, but the five most important include pyrope and almandite (the combination of which creates rhodolite), spessartite, grossularite or grossularite (which includes hessonite and tsavorite), and andradite (which includes demantoid). Garnets of all species are the birthstone for January, so January babies aren't limited to the well-known red varieties.
A bright grass-green to olive or yellowish green gemstone first discovered in Canada. Gaspéite is commonly used to carved into artistic sculptures. This stone can be faceted or cut as cabochons and set in jewelry.
Gadolinium gallium garnet, thankfully abbreviated to GGG, is a man-made diamond simulant that entered the market in the 1960's. Today it is rarely used as a gemstone, and is instead manufactured for optical and industrial uses. The Czochralski method of gem synthesis involves the melting of various elements in a platinum crucible. A small gem crystal (called a seed) and attached to a rod is then dipped into the melt and slowly pulled away as the crystal grows around the seed. For this reason, the Czochralski method is also known as crystal pulling. Synthetic gems have the same chemical, optical, and physical properties of their natural counterparts, but are a more cost-effective alternative to a natural gem.
Glass has been used for thousands of years as a decoration. It is sometimes employed as a gemstone simulant, but is often appreciated entirely upon its own merits, especially when formed with a high level of artistry.
Goldenite comes in white and black varieties coated with a patterned gold layer. The black stones are hornblende a common natural rock composed primarily of iron, magnesium, potassium, and calcium. The white stones are white quartzite, a rock made up of interlocking quartz grains.
Goldstone is glass that contains myriad of tiny angular crystals of copper. First made in Italy, goldstone forms by reduction of particles of copper oxide within the glass during a process called annealing. Nothing in nature looks quite like glittering goldstone. Made in three distinct colors (blue, green and orange), goldstone is a tough and durable material that can be made in large pieces and fashioned into slices and objects of almost any desired size and configuration.
While most members of the beryl family such as emerald or aquamarine are famous for their colors, goshenite is the highly collectible colorless variety that displays a diamond-like fiery brilliance. Interestingly, pure beryl is colorless, with traces of different metallic elements being responsible for this gem family's great color range. Always limited in availability, goshenite is named for the locale where it was first discovered--Goshen, Massachusetts.
Grandidierite is a greenish blue or bluish green mineral named after French explorer and naturalist Alfred Grandidier. The mineral was originally discovered on the southern coast of Madagascar in the Andrahomana area. A new gem quality deposit was found near Tranomaro, Madagascar in 2014.
The first grossular garnet specimens discovered were pale green and similar in color to the gooseberry. This species of garnet gets its name from the Latin name for gooseberry "Grossularia". Not all grossular garnets are green. Most grossular garnets are better known by their variety names hessonite, tsavorite, mint, leuco garnet, and hydrogrossular.
Gypsum is a mineral that has been utilized since antiquity. This soft mineral represents the second level on the Mohs hardness scale. Cut stones are rare because gypsum has perfect cleavage, and it is too soft to facet. The fine-grained variety known as alabaster is used for carvings and decorative objects. Selenite is the large crystalline variety that is popular with mineral collectors. The fibrous variety is known as satin spar. Gypsum sometimes crystallizes in rosette patterns known as desert roses. Gypsum is probably best known for its use in construction materials like sheetrock, cement, and plaster.
Discovered in Greenland in the late 1890's, hackmanite is named for Finnish geologist Victor Hackman. It is a rare occurrence to find gem-grade hackmanite; at best, most crystals are translucent. Hackmanite is the light pink to pale violet variety of sodalite. It is a particularly unusual gem because it exhibits a special optical property known as "tenebrescence," a type of reversible photochromism. This feature allows the gems to temporarily change color when exposed to different light forms. While hackmanite gems are usually pink to violet, the color quickly fades to gray or greenish-white in sunlight, and will slowly return to the original color after changing the light. Its tenebrescent property makes hackmanite a prized mineral for collectors.
Hambergite is an often colorless gemstone named in honor of Swedish mineralogist A. Hamberg. While it is durable enough to wear in jewelry, hambergite is most commonly seen in specimen form. Rarely is a specimen flawless, and it can be easily confused with colorless quartz since they are similar in appearance. A unique characteristic of hambergite is its prefect cleavage that makes faceting into a gemstone very difficult for cutters.
Hausmannite is a brown to black mineral that is part of the spinel group. It was named after Johann Friedrich Ludwig Hausmann who was a professor of mineralogy at the University of Göttingen in Germany. Some of the finest samples come from Namibia and South Africa.
Haüyne is an extremely rare mineral and even rarer gemstone. Its bright blue color is common for this stone, but it can be found in white, gray, yellow, green, and pink colors too. Lazurite the sulfur rich variety of haüyne is what gives lapis lazuli its blue color. The best-known specimens have been found in Eifel Mountains of Germany.
Also known as Mount St. Helens stone, helenite is a man-made stone that originates from the ashes of the Washington State Mount St. Helens eruption in 1980. While the volcanic ash was being removed, it was discovered that it contained glass particles that turned a beautiful green color when heated. This glass is commonly made and fashioned into jewels that may be green, red or blue.
Displaying characteristic yellow to orangish yellow and greenish yellow, heliodor is the most cheerful variety of beryl. Interestingly, as an allochromatic gem, pure beryl is colorless, with traces of different elements responsible for beryl's wide range of colors. Heliodor is named from ancient Greek words meaning "gift from the sun," as it was once believed that heliodor harnessed the power and warmth of the sun and was responsible for the change between day and night.
Hematine is a hematite simulant sometimes called hemalyke, hemalike, or magnetic hematite. It was originally reported to be pressed and sintered iron oxide, but most material currently on the market is a ceramic-like material composed of barium-strontium ferrite. Hematine is highly magnetic, whereas hematite is not.
Hematite is a dark gray to black mineral known to various cultures throughout history. Babylonians, Egyptians, Greeks, and Romans were a few of the civilizations that made use of this mineral. Hematite derives its name from a Greek word for blood, an allusion to the reddish powder produced during the fashioning process due to the presence of iron.
Found in several worldwide locations that are often zinc-rich environments, most hemimorphite crystals are white to grayish white, yellowish or totally colorless. But when the robin's egg blue hues are found, miners know they have hit a pocket of true gem-quality material. Not only is fine quality hemimorphite geologically scarce, but there are few locations that have the right combination of trace minerals that create this stunning blue color. This gem is often appreciated as natural specimens due to its almost bubbly botryoidal crystal habit.
Herderite is a rare collector’s gem, typically found in smaller sizes. This mineral occurs in green, bluish green, white, colorless, yellowish, or gray. Herderite was first discovered in Germany in 1828, but Brazil is today's dominant source. Collectors treasure herderite for cyclic and “fishtail” twinned crystals. Some specimens exhibit phosphorescence when exposed to X-rays.
Nicknamed the "cinnamon stone", hessonite is a variety of grossular garnet and the color ranges from golden yellow to brownish orange or brownish red, as well as reddish orange to red. A perfectly colored hessonite is a bright golden orange that resembles a combination of honey and orange with an internal fire. Some hessonites have tints of brownish red that resembles the color of cinnamon. Hessonite can be found in the gem gravels of Sri Lanka, but it is also found in Brazil, Canada, Italy, Myanmar, Russia, and the United States. While the clearest gems are the most prized, inclusions in hessonite are common, and often give stones an oily or roiled appearance.
Heulandite is a zeolite mineral named for Johann Heinrich "John Henry" Heuland. Crystals are often bladed with a pearly luster.
Hickoryite is a red, pink, and yellow banded variety of Rhyolite that comes from Rodeo, State of Durango, Mexico. Autumn or rainbow hickoryite is mostly brown or tan with red, pink, or yellow bands.
Hiddenite is the green chromium-rich variety of spodumene, which is rarer than its pink sibling, kunzite. Hiddenite is named for American gemologist William Hidden, who first discovered this transparent green variety in North Carolina in the area that now also bears its name, Hiddenite.
Natural animal horns have been used for both practical purposes and adornment for millennia. Horn is distinctively beautiful with natural earthy to golden and one-of-a-kind color variations. Its soft nature lends to ornate carving.
Not well known to the general public, howlite is one of those minerals that is almost more famous for imitating another mineral. In this case, the other mineral is turquoise, a phosphate gemstone. Howlite is naturally milky white in color and often has dark vein-like mineral inclusions. Because of its porosity, it accepts dye fairly easily, achieving a turquoise-like blue color. Howlite accepts a nice polish and its porcelain-like luster is appealing.
Hydroxyapophyllite crystals are tabular and are frequently striated. It is typically colorless or white, but can be pink, light green, pale yellow, blue, brown, or violet. The mineral can be found in Jefferson, NC and Kimberley, South Africa.
Hypersthene is a common mineral in the pyroxene group that rarely forms distinct crystals. Hypersthene is similar in appearance to hornblende, but it is a harder material. Since the hardness difference was the main way to tell the stones apart the Greek words “hyper” meaning above and “stenos” meaning power gave the inspiration for the name. It is usually brown, green, or gray with vitreous to pearly luster and displays a brilliant coppery metallic surface sheen.
Idocrase, also known as vesuvianite after its discovery at Mount Vesuvius, has crystals that are prismatic and glassy. It is usually green or chartreuse in color, but may be found in yellow to brown, yellow-green, red, black, blue or purple hues.
Ilvaite is name after the “Ilva” the Latin name for the island of Elba, Italy. It is black and forms in prismatic columns or large masses of indistinguishable crystals.
Indicolite is one of the most valuable and collectible of all elbaite tourmalines, with hues spanning from lighter to deep, intense blues. Cutting indicolite can be a task for even the most skilled of cutters, as it is strongly pleochroic and appears darker when viewed down the crystal. This factor must be taken into consideration when cutting, as a loss of transparency and brilliance can occur in darker specimens.
Inesite is part of the triclinic crystal system. It typically has pink spindly crystals that radiate out in fan like clusters. The mineral gets its name from the Greek word for “flesh fibers” due to its appearance. It is a late-stage hydrothermal mineral found in manganese deposits.
Iolite is the gem-quality blue or blue-violet variety of cordierite. While iolite enjoyed popularity in jewelry in 18th-century Europe, this naturally beautiful gemstone is relatively new to today's jewelry market, and is regaining popularity with the public. Because of its varying levels of hardness and strong pleochroism, iolite is one of the most difficult stones for lapidaries to fashion. It must be cut in certain directions to take advantage of the best color, which can be tough when the shape of the rough doesn't lend itself to cutting in that same direction.
Ivory has long been treasured for its beautiful white color and ability to be finely carved. As opposed to bone or horn, ivory is derived from the teeth and tusks of animals. Because of the devastating impact of poaching due to the ivory trade, the importation and sale of such materials is severely restricted or banned in many countries.
The term jade is used for jadeite and nephrite jade. For centuries the two materials were considered one and the same. It was not until 1863 that they were identified as different minerals with a similar appearance and properties. Jadeite jade is a member of the pyroxene group and is primarily composed of the mineral jadeite. Nephrite is a tough rock comprised of intergrown crystals of minerals from the tremolite-actinolite solid solution series, part of the amphibole group.
Jade has been treasured for some 7,000 years for its unique luster, lovely color and impeccable toughness. This precious gem has always had special significance in many Asian cultures, and can be compared to the West's admiration of diamonds and gold. For centuries, nephrite jade and jadeite were considered one and the same. It was not until 1863 that they were identified as different minerals with a similar appearance and properties.
Jasper is an opaque, fine grained variety of chalcedony quartz. It is typically found in red, yellow, brown or green colors and is generally spotted with these colors. Its name comes from the Latin word for the gem, iaspis, meaning "spotted stone."
Jeremejevite was named for a Russian mineralogist in 1883, but there are rarely any specimens found in Russia today. Recently Namibia has started to produce some mentionable crystals, but in such small amounts the stone is still very rare. Jeremejevite is typically found in pale blue-green, cornflower-blue to yellowish brown hues.
Jet is generally classified as a lignite coal and has a high carbon content and a layered structure. It is typically black to dark brown and can sometimes contain tiny inclusions of pyrite. Jet has been carved for ornamental purposes since prehistoric times. The term “jet black” gets its name from the color of jet. There is hard jet that forms in saltwater and soft jet that forms in freshwater.
In 1996 a German company started marketing Japanese Freshwater Pearls as Kasumiga Pearls. The average size of these are between 10mm to 15mm but can grow up to 20mm. Kasumiga Pearls are known for their excellent color and luster. The most valuable pearls are round to near round but they also come in interesting baroque shapes.
Kornerupine comes in colors ranging from brown to beautiful emerald green to shades of yellow. It has distinctive trichroic pleochroism. Star material has been found in Mogok, Myanmar and is due to tiny rutile and graphite inclusions. Because of its extreme rarity, kornerupine is a highly sought-after collectors stone.
Kunzite is the pink to violetish purple variety of spodumene. The stone gets its color from trace amounts of manganese. Kunzite is better known than other spodumene varieties like hiddenite (green) and triphane (yellow). To obtain the best color and saturation in a stone it must be faceted with the table perpendicular to the length of the rough crystal. Kunzite often forms in large crystals that are highly sought after by mineral collectors. Kunzite displays strong fluorescence and phosphorescence that also makes it attractive fluorescent mineral collectors.
Kyanite is named for the Greek word for blue, kyanos. And what a blue! Fine Nepali kyanite can resemble the finest sapphire. Kyanite was a gem far better known to mineral collectors until more recent finds in the Kali Gandaki river region of west central Nepal, the first source to produce a significant amount of facet grade kyanite. Prior to the Nepal discoveries, Brazil was a major source of mineral specimen material, but kyanite also occurs in a variety of locations around the world. More recent kyanite discoveries have yielded additional colors, including orange and green.
Labradorite is a plagioclase feldspar. The phenomenal variety that shows labradorescence is the best-known variety, but rainbow moonstone, Oregon sunstone, and transparent yellow labradorite are also labradorite feldspars. Displaying brilliant pastels and deep golden colors, phenomenal labradorite features a spellbinding "black rainbow" of color. When appreciating the iridescent play of colors known as labradorescence, observe the strength and intensity by viewing from different angles, as different colors or even a range of colors may be visible from different positions. Rainbow moonstone has the best transparency of all the moonstone varieties. Labradorite sunstone is the only sunstone variety that contains copper platelets. The large sizes and clarity of yellow labradorite makes it a favorite of gemcutters.
Discover the mystical allure of rich, royal blue and sparkling golden specks found in lapis lazuli. Very few gems have such a long and storied history as lapis lazuli. Along with carnelian, it is the oldest known gemstones to be appreciated and worn as adornment. When lapis lazuli was first introduced to Europe, it was called ultramarine, meaning "beyond the sea." The gem was ground to a powder for use as early eye shadow, and as pigment for early oil paints. Today, this rich blue gem still retains the allure that first captivated humans thousands of years ago.
Larimar is a rare blue to green variety of pectolite, a mineral prized mainly by specimen collectors. While pectolite may be found in several locations, including Canada, England, and the U.S., larimar is found only in the Dominican Republic. This unique blue gem formed from volcanic activity millions of years ago that created the Caribbean island of Hispaniola. The most prized larimar exhibits sky blue color with a white pattern throughout, reminiscent of sunlight dancing on the floor of a pool. This gem was named by its discoverer for both his daughter, Larissa, and el mar, the sea.
Larvikite is a feldspar-rich igneous rock, called a monzonite and is named for the town in Norway where it was found. One characteristic of this stone is its blue sheen or labradorescence, caused by the presence of interlocking feldspar crystals within the structure of the stone. Through the wonders of nature, each polished gem has a sheen that sparkles with deep silver tones. Usually, this stone is used in ornamental and decorative purposes.
Also known as scoria, lava rock is formed from solidified volcanic lava. A defining feature of this rock is cavities caused by trapped gas bubbles. Unlike pumice, however, lava rock does not float on water. The unique look of this highly porous rock, along with its relatively light weight, makes it popular for jewelry and ornamental carvings.
This mineral species can be opaque to crystalline transparent. The color of lazulite ranges from medium to dark greenish blue to violet blue and is often mottled with white. When fashioned into gems, finished stones typically weigh less than 5 carats. A separate mineral species, lazulite should not be confused with lazurite or azurite.
Lazurite is a richly colored blue mineral primarily seen in cabochon gems or carvings. Lazurite is a major component of lapis lazuli, giving the stone its brilliant blue color. Lazurite crystals are rare, as the gem is most commonly found in massive form and rarely as well-formed crystals.
Lepidolite is a beautiful lithium-rich member of the mica mineral family. Violet to pink in color, lepidolite has a scaly appearance seen in many specimens. This gemstone is not commonly known to be faceted and is primarily used in ornamental and decorative pieces.
Liddicoatite is a calcium-rich lithium species of tourmaline named in 1977 in honor of noted gemologist Richard T. Liddicoat. Gems may form in green, pink, red, blue and purple colors, sometimes with internal multicolor banding and zoning. Large crystals are often sliced to display their natural multicolor designs.
Limestone is composed mainly of calcite and occurs in thick extensive, multiple layers. It is formed in shallow seas from a combination of calcium carbonate or the accumulation of shells and skeletons of calcareous marine organisms. Limestone is abundant and is very important commercially as it has a number of different uses as a building stone, cement and as a raw material in the glass manufacturing process. Limestone that is recrystallized under heat and pressure becomes marble.
Limonite gets its name from the Greek words for “marshy lake” because it is found in marshes. Limonite is a mineraloid that contains varied amounts of goethite and hematite, forming from weathering of hematite, magnetite, and pyrite. It is often found as a pseudomorph as it replaces other minerals.
The shell of the Pteria penguin, better known as the penguin's wing oyster, have a wing-like extension on one side of the shell is called “Mabé gai” in Japanese. The name “Mabé pearl” is inspired by this reference. The shells of the Pteria penguin and the Pinctada maxima are used to create blister pearls. The Haliotis variety of Abalone has also been used to create “Mabé pearls”. A plastic or wax half or three-quarter spherical or pear-shaped or heart-shaped nucleus is glued to the inside of shell. After two or three years of nacre growth the blister pearl is cut out of the shell. The nucleus is then removed and filled with resin and is backed with mother-of-pearl. The sizes range from 12mm to 25mm. They are more affordable than true cultured pearls.
The Madeira name comes from the Brazilian word meaning ‘wood’ or ‘wood colored’. Most madeira citrine comes from heating amethyst with a brownish core to get the warm yellow or orange color. The primary sources come from the Brazilian state of Rio Grande do Sul, Uruguay, Zambia, and Madagascar.
Magnesite, a member of the calcite mineral group, is often found in massive form, as well-formed transparent crystals are rare. Pure magnesite crystals are colorless, and any impurities present affect their color which is typically light yellow to brown or gray. Magnesite has perfect cleavage in three directions, making faceting extremely difficult. Faceted gems are often found in private collections or museums.
Malachite is generally opaque and comes in a vivid bluish green to green color. It is usually banded in two or more tones of green and may have a subtle sheen. This gem is a secondary copper mineral and is commonly found in conjunction with azurite, a bold blue copper carbonate mineral. A mix of the two minerals is often called azurmalachite.
Marble is a metamorphic rock formed under the influence of heat and pressure and consists of a mass of interlocking calcite or dolomite crystals. Pure marble is white, and some other marbles take their common names from their color or mineral impurities. Marble is often used for fine building material or sculpture, thanks to its beautiful appearance.
Marcasite is a polymorph of pyrite. It has the same chemistry, but a different crystal structure. In the jewelry trade, the names pyrite and marcasite are often used interchangeably. Marcasite is often cut and polished in a cone or pyramid shape and pave set between sterling silver beads to enhance their brilliance.
Maw-sit-sit is a rock composed primarily of kosmochlor with varying combinations and amounts of other minerals. Due to its close resemblance to jade, it was believed to be a variety of jade up until the 1960s. This gem is opaque saturated green with dark green to black veining or mottling.
Melo Melo Pearl
The Melo Melo pearl comes from the Melo Melo sea snail, a group of sea snails with scroll-like volute shells found in the South China Sea. The melo pearl is a non-nacreous pearl with colors ranging from light tan to brown, but orange is the most sought-after color. Melo Melo pearls are extremely rare, as no harvesting techniques exist.
Mesolite is a zeolite mineral that occurs in delicate, needle-like crystal structures that radiate from its base. Prized by collectors for its striking crystal formation, mesolite is typically white or colorless, but occasionally light yellow in color. Large specimens are very rare, and faceted gems are almost non-existent.
A meteorite is a solid piece of debris that originated in outer space, entered Earth's atmosphere, and survived impact with the surface. These fragments are usually from comets or asteroids, or debris from the Moon or Mars. There are several known meteorite impact sites, including Campo Del Cielo, Argentina, the Sikhote Alin Mountains in Primorye, Russia, and the Sahara Desert region of Morocco. Meteorites are separated into three types based on their metal content: iron, stony-iron and stony.
Mimetite is a lead-arsenate mineral belonging to the apatite group. It forms a series with vanadinite and pyromorphite. For this reason, the mineral is named for the Greek word for imitator due to its resemblance to pyromorphite.
Synthetic moissanite is an incredibly durable gem. In fact, the ceramic version of synthetic moissanite, called synthetic silicon carbide, is so hard and tough that it is used for body armor and mirrors in orbiting space telescopes! Fortunately, it also makes a gorgeous gem. Synthetic moissanite has a higher dispersion value (fire) than diamond, making it an impressive jewel. Each lab created gem is faceted by a skilled cutter to maximize its brilliance and enhance its exceptional fire. Second in hardness only to diamond, it is extremely resistant to scratching, abrasion, breaking and chipping.
Moldavite is a silica rich tektite found near the Moldau River in Czechia. Moldavite is a natural glass formed as a result of a meteorite impact with the earth. It was first discovered in the late 1700’s in what was then known as western Moravia. The colors of moldavite range from yellowish green to green and brownish green.
Montebrasite is a light green to yellow or colorless gemstone that belongs to the amblygonite group. Similar to amblygonite in chemical composition, it has less fluorine content and twinned crystals are common. Montebrasite was named for its discovery in Montebras, France.
Mookaite comes in the warm earthy colors of reds, yellows, and browns. It is a silica-rich porcelanite (a natural ceramic) created by the weathering of a special rock deposit in Western Australia. It owes its bold colors and texture to its variable composition. In 2011 pink mookaite was discovered at the Binthalya prospect.
Moonstone is a variety of feldspar that displays an amazing optical phenomenon called adularescence. Internally repeating feldspar layers scatter the light that enters the stone, creating a mystical glow reminiscent of moonbeams. This glow comes to life, rolling across the gem’s surface, when it is moved. Adularescent labradorite with a multi-colored glow is sometimes called Rainbow Moonstone.
Morganite is the pretty, peachy-pink variety of beryl, cousin to more familiar beryl varieties, emerald and aquamarine. Morganite's beautiful, feminine colors are a result of the presence of manganese and iron. After its 1910 discovery in Madagascar, the famous gemologist George F. Kunz proposed to name the gem in honor of financier and gem enthusiast J. P. Morgan. Morganite has many redeeming qualities, including good Mohs hardness, luster, and clarity. The two major sources are Brazil and Madagascar. Stones also come from Afghanistan, China, Mozambique, Namibia, Pakistan, Russia, and the United States. Quality morganite stones in large sizes remain relatively rare.
Mother-of-pearl is the nacreous iridescent inside layer of certain mollusks. This beautiful substance is often used for jewelry, carving and ornamentation. As mother-of-pearl producing mollusks cannot regulate their body temperature, they are susceptible to changes in external conditions. Mother-of-pearl can naturally appear in a wide variety of colors, however, it is frequently dyed to a multitude of attractive shades.
The Italian glass industry dates to the 8th century. In 1291, Venetian glassmakers were ordered to move to the island of Murano to prevent fire from destroying the wooden buildings of Venice. Glass artisans handed down their knowledge and skills through the generations. The Murano artists are forever innovating, and they are known for their use of color and intricate glass decorations.
Muscovite specimens are prized by collectors. Muscovite Mica is commonly used as a component in cosmetics, like eyeshadow, to produce shimmer.
The chemical vapor deposition (CVD) process deposits a thin film onto part of the surface of a colorless quartz gemstone, creating an eye-catching rainbow effect as light passes through the gem, which results in an unbelievable array of colors.
With its dazzling kaleidoscope of colors, Mystic Topaz® first appeared in September 1998 at the Hong Kong Jewelry Fair, but it took a few years for designers and high-end jewelry manufacturers to realize its unquestionable charm. Mystic Topaz® begins with a natural topaz gemstone that was created millions of years ago, that is then made even more beautiful and desirable with the assistance of modern technology. The chemical vapor deposition (CVD) process deposits a thin film onto part of the surface of a white topaz gem, creating an eye-catching rainbow effect as light passes through the gem, which results in an unbelievable array of colors.
Nanocrystal is glass-ceramic material developed in the 1970’s. Nanocrystal can simulate most gem materials and comes in a variety of colors and transparencies.
Natrolite is a zeolite mineral named for the Greek word natron, meaning "soda," due to the presence of sodium in the stone. Its range of colors include yellow, gray, and brown, to colorless. Occasionally, it is found in pale yellow to red hues. Crystals often grow in long, needle-like formations, and are especially prized by specimen collectors.
Jade has been treasured for some 7,000 years for its unique luster, lovely color and impeccable toughness. This precious gem has always had special significance in many Asian cultures and can be compared to the West's admiration of diamonds and gold. For centuries, nephrite jade and jadeite were considered one and the same. It was not until 1863 that they were identified as different minerals with a similar appearance and properties. Nephrite is a tough rock comprised of intergrown crystals of minerals from the tremolite-actinolite solid solution series, part of the amphibole group.
Nifontovite is a very rare member of the borate family of minerals. Named for Russian geologist Roman V. Nifontov who discovered it in 1961, nifontovite is found in few locations worldwide, including Russia, Mexico and Japan. Mexico is producing the cleanest and largest specimens at this time. Typically, nifontovite is transparent and typically colorless or gray with a vitreous luster. A nifontivite gem, donated in 2009, resides in the Smithsonian's National Gem Collection.
Obsidian has been used since the Stone Age for tools, weapons and as an ornamental material. It is used in modern times for scalpel blades. Obsidian is formed by the rapid cooling of viscous lava due to volcanic explosions. It consists of the same minerals as granite but cools so quickly that they do not have time to crystallize. Obsidian has a glassy luster and is usually black or very dark green, but it can also be found in an almost colorless form.
Named for the German biologist Lorenz Oken. Specimens often found as “cotton ball” formations because the crystals are straight and fibrous and they radiate out in orb like structures.
Oligoclase is a member of the plagioclase feldspar group. Two oligoclase varieties, sunstone and moonstone, are prized for their phenomenal optical properties.
Olmiite was officially named as a new species in 2006. It is the Manganese dominant analog of poldervaartite. It is named after the Italian mineralogist Filippo Olmi. The only known location where olmiite is found is the N’Chwaning II mine, Kalahari field, Republic of South Africa.
Onyx is the dark brown to black variety of agate, a cryptocrystalline quartz. Since ancient times onyx has afforded gem cutters and carvers an excellent source for carving cameos, intaglios, and other jewelry creations. Inexpensive, abundant, and available in large sizes, onyx is also a favored stone when fashioning cabochon gems and beads.
While we often think of opal in terms of phenomenal play of color, this gemstone family is full of other unique and appealing members that have their own allure. Gems can be transparent, translucent or opaque and form in almost any color in many locations around the world. Get to know all the varieties of this unique family by looking at our fire opal, dendritic opal, hyalite, Caramel Spice Opal (TM), Morado Opal (TM), along with even more blue, pink and green varieties. With such an endless array, opal truly is the 'Queen of Gemstones'.
Opalite is a man-made opalescent glass. When opalite is placed against a dark backdrop, it takes on a luminous blue or pink glow. Blue opalite has even been confused for moonstone at times.
Orpiment is an arsenic sulfide that grows in small masses with lemon-yellow to brownish-yellow coloring. Its name comes from a Latin term meaning "gold pigment," as this mineral was once used to make yellow paint. This gem is photosensitive and should not be exposed to light for prolonged periods.
Orthoclase is part of the feldspar mineral family, one of the most abundant mineral families in the world. It is a common constituent in granite used for industrial purposes. For example, "Black Pearl" granite countertops are composed mostly of feldspar. While orthoclase, a potassium-rich feldspar, is better known to collectors, there is one variety that many are familiar with: moonstone, prized for its shimmering adularescence.
While sapphires have mesmerized gem and jewelry connoisseurs since the dawn of time, one fancy sapphire variety has a distinct allure and prestige all its own: padparadscha sapphire. Padparadscha sapphire derives its name from the Sanskrit padma ranga, meaning “lotus color,” for its resemblance to the famed lotus flowers of Sri Lanka, where the gem was originally found. Padparadscha sapphires traditionally must combine elements of pink and orange in one gem to rightly claim their padparadscha title, though the coloration requirements are highly disputed.
Literally translating as “landscape stone,” paesina pietra is an ancient marvel of nature. Created 40-50 million years ago, picturesque scenes that often mimic those seen in everyday life were formed within limestone rock. Seen in a variety of colors and an infinite number of designs, these sedimentary stones were created as the earth shifted, forming fractures in the limestone. Composed primarily of compressed limestone and clay that formed in seabeds, it was the infiltration of iron and manganese hydroxide that created their variety of scenic patterns and array of colors. Paesina pietra has been collected as an objet d 'art since the 17th century throughout Europe. Highly regarded as a decorative accent, the stones were displayed prominently in European royal courts, including those of France, Germany, and England.
Pargasite mostly occurs in a brown color, but has been found in greenish-brown to dark green and black. This gemstone was first found in Finland in 1814 and is named for its site of discovery. A member of the amphibole group, pargasite is closely related to hornblende. Some fine specimens of this rare gemstone have been faceted.
Pectolite has crystals that are elongated and flattened, but it more often occurs as acicular sprays or radially fibrous masses. It may be white, pale tan, or pale blue to greenish. Pectolite occurs widely in Canada, England, and the United States.
August's birthstone, peridot, is a relatively inexpensive, beautiful gem with a pedigree dating back as far as early Egyptians. Among its accolades, peridot can count being a favorite among royals and clergy, used to adorn everything from a queen's crown to a knight's sword. Peridot jewels were actually among Cleopatra's beloved treasures, though she believed them to be emeralds, as gems were then classified solely by color. Prized for its all natural, unenhanced range of colors, peridot is the gem variety of olivine and exhibits colors ranging from golden lime greens to rich grass greens.
Faceted petalite gems and specimens are prized by gemstone and mineral collectors. Petalite's name is derived from the Greek petalos (leaf), referring to its perfect cleavage. Colorless material is common, and large crystals have been mined. Other petalite colors include white to yellow or gray, yellowish green to light green and pink. Crystals range from transparent to translucent and are prized for their good clarity. Faceted gems aren't often seen due to petalite's cleavage planes.
Petrified wood is the fossilized remains of what once was wood. The material became petrified over time by the invasion of minerals into cavities between and within the cells of natural wood. Instead of decaying, the organic materials in the wood were replaced with minerals, primarily silicate of quartz, without changing the original structure of the wood.
Displaying gorgeous deep raspberry pinks, pezzottaite is a relatively new gemstone that has been subject to much confusion due to its similarities with red beryl. Pezzottaite has a variety of misnomer trade names including Madagascan raspberyl, raspberyl and raspberry beryl. Pezzottaite was first thought to be a new variety of beryl. Pezzottaite upon analysis was found to be a new mineral variety, with a trigonal crystal structure and that it contained cesium and lithium, which differed from beryl, making its trade names misleading.
A rare beryllium mineral, phenakite was named in 1833 from the Greek word for "deceiver," alluding to its similar appearance to quartz. Its crystals are predominantly rhombohedral, and less commonly short and prismatic. Phenakite's rarity, hardness, lack of cleavage and high clarity make it a great option for collectors.
Phosphosiderite is a vibrant purple orchid color and is a relative newcomer to the world of gemstones as it was only discovered in the late 19th century. Fine quality phosphosiderite is hard to come by and this opaque gemstone may contain veins of yellow. In addition to purple, phosphosiderite occurs in colors ranging from white, pink, red, violet red and colorless.
Pietersite is a striking variety of chalcedony that comes primarily from Namibia and, more recently, China. It commonly exhibits various shades of color, ranging from blue to gray and red to yellow and brown. Pietersite displays chatoyancy similar to tigers eye quartz.
Natural pink opal has no play of color and is a mixture of opal, palygorskite and chalcedony. Nicknamed the 'pink Andes opal', the soft pinks of this opal are appreciated as an environmentally friendly alternative to conch pearls as well as pink coral. Today, Peru is the major producer of this most feminine opal variety that is often carved into beads and occasionally faceted into gems.
Poldervaartite can be found in a light orange-pink to milky-white color. High-quality poldervaartite specimens are prized by collectors and facetable material is rare.
Pollucite is often found in association with petalite (formally known as castorite). It was named after the twin brothers Pollux and Castor in Greek mythology. It is an important source of cesium. Facet grade material is prized by gemstone collectors and can be found in Afghanistan, Pakistan, Russia, and the United States.
Polymer clay is made from PVC resin and a liquid plasticizer. It is pliable until baked in an oven. Jewelers use polymer clay to create colorful beads, pendants, earrings, and bracelets in fanciful designs. Since the material can be molded into any shape, cut with simple tools, and embellished with paint, the only limit to its use is the artist’s imagination.
Prase is a dull green to yellowish green variety of chalcedony, a cryptocrystalline quartz. It is commonly fashioned en cabochon to show off its leek-green color. Prase can be confused with chrysoprase since they are very similar in appearance, but a darker, less saturated color is typically indicative of prase.
A pastel dream, this variety of quartz boasts a beautiful soft green color. Sometimes incorrectly referred to by the misnomers "green amethyst" or "lime citrine," prasiolite is rarely found in nature, so most material available on the market is produced by heating or irradiating amethyst. Prasiolite is an exciting gem in that it is readily available in large sizes with high transparency and great durability.
Prehnite is the first gemstone named for a person. It was named in honor of Colonel Hendrik Von Prehn, the Dutch mineralogist credited with its discovery in the 1700's in South Africa. Also, prehnite was the first mineral to be named and described from South Africa, long before the country became an important source for precious gems, including diamond. Many specimens of this gem have an interesting luminous quality, with a vitreous to greasy luster. With color ranging from pale green to a pale yellowish green and a hardness of 6 - 6.5, Prehnite is considered to be fairly sturdy and long wearing when set in jewelry.
Preseli Bluestone is found in the Preseli Hills located in Pembrokeshire in western Wales. Preseli Bluestone is spotted Dolerite which is a type of igneous rock that contains spots or clusters of plagioclase feldspar that make each distinctively different from the next. It is a medium-grained, heavy rock that is harder than granite. Preseli Bluestone was used in the construction of the inner rock circle at Stonehenge. It is widely believed these multi-ton stones were carried nearly 200 miles from the Preseli Hills in Wales to Stonehenge around 2300BC during the third phase of its construction and aligned to the summer solstice. Perseli bluestone tools, such as axes, that were made by ancient civilizations have been found all over the British Isles.
The name Psilomelane was discredited as a distinct mineral variety but the name is still used as group name for hard black manganese oxides of which Romanechite and Hollandite are components. Psilomelane means smooth and black in Greek which aptly describes its appearance. It is often found in botryoidal masses with submetallic luster.
Pyrite has a shiny golden-yellow color and a metallic luster. Its name comes from the Greek word pyr, meaning "a gemstone that strikes fire," due to the sparks produced when pyrite strikes iron. While pyrite has a history of being mistaken for gold, it is differentiated by pyrite's lighter, tougher, broken-faced grains. You may hear pyrite called by its nickname "fool's gold." Marcasite is a polymorph of pyrite. It has the same chemistry, but a different crystal structure. In the jewelry trade, the names pyrite and marcasite are often used interchangeably.
Pyromorphite is a member of the apatite family of minerals. Faceted stones are very rare and its colors are usually brown, green, orange, yellow, colorless, gray and white. Pyromorphite was named in 1813 from the Greek words for "fire" and "form" because, after being melted, the mineral will take on a crystalline shape upon cooling.
Hear the word "garnet," and what invariably comes to mind is the image of the deep red pyrope garnets belonging to the pyralspites family. Pyrope comes from the Greek words pyr and ops, meaning "fire eye." The rich reds are both affordable and beautiful, perfect for not only gemstone collections, but jewelry as well.
Among America's rarest and most stunning pearls, quahog pearls were first valued by Native Americans along the coast of New England. This non-nacreous calcareous concretion forms in colors from white to brown, to purple and lilac in round, button and teardrop shapes. Such pearls are typically collected by fishermen as a result of harvesting the meat of the shellfish.
Quartz is the name of a large group of minerals comprised of silicon dioxide. Quartz is the most abundant mineral on the Earth’s surface, and it can be found on all seven continents. It is best known as its gemstone varieties Amethyst, Citrine, and Rock Crystal Quartz. Quartz crystals are distinctive six-sided prisms with six-sided pyramid terminations. Quartz specimens are attractive and sought after as decorative items.
Quartzite is a metamorphic rock formed when sandstone, which is composed of tiny grains of quartz, is subjected to heat and pressure under Earth’s surface, fusing the sand grains together. The result is an extremely durable rock that can also be dyed to attractive colors.
Adularescent labradorite with a multi-colored glow is sometimes called rainbow moonstone. Rainbow moonstone is colorless and highly transparent and it displays an amazing optical phenomenon called adularescence. Labradorite is a plagioclase feldspar and a member of the triclinic crystal system. Internally repeating feldspar layers scatter the light that enters the stone creating a mystical glow reminiscent of moonbeams. This glow comes to life, rolling across the gems surface, when it is moved.
One of nature's more exotic treasures, rhodochrosite is a manganese carbonate that gets its name from two Greek words, rhodon meaning “rose” and chros, meaning “color.” This is a fitting name, indeed, as its finest colors range from very pale pink, to deep orangey red. Yellow to brown crystals are also known. Rhodochrosite comes in transparent, semi-translucent, and opaque varieties. Semi-translucent to opaque rhodochrosite is often carved or cut en cabochon and typically displays "bacon strip" or "bull's eye" patterns.
Unusually striking, rhodolite is a naturally occurring blend of almandite and pyrope garnet. While raspberry and grape are the most prized colors, rhodolite is also found in shades of purplish red to reddish purple. The name is derived from the Greek rhodon, meaning “rose,” and lithos, meaning “stone.” Rhodolite is typically found as water-worn pebbles in alluvial deposits, but it is also occasionally mined directly from host metamorphic rock. Tough, durable, never enhanced and easily cleaned, rhodolite is ideal for jewelry. Due to its bright transparent clarity, rhodolite is often cut into fantasy shapes.
Rhodonite is an attractive mineral that is primarily known as an ornamental stone but is often seen in jewelry in the form of beads or cabochons. This mineral easily falls into the category of rare and exotic, making it highly prized by collectors of specimens and gemstones. Its name, derived from two Greek roots, means "rose-colored stone." Rhodonite, which is commonly found in massive or granular forms, is most often translucent to opaque in appearance. On rare occasion, transparent, gem-quality material may be found. Rhodonite's natural color ranges from pink to rose red to brownish red, often with blackish veins throughout.
Rhyolite is a volcanic rock similar in its chemistry to granite. Most rhyolites are porphyritic, with larger crystals in a fine-grained matrix of crystals too small to be seen with the naked eye. Rhyolite is silica-rich, giving it a light range of color, often found with banding throughout. This beautiful stone is often used in ornamentation.
Richterite is a member of the amphibole group of minerals, named after German chemist Hieronymus Richter. Typically, richterite is near colorless to brown. If richterite is dominantly composed of potassium, it can be blue. In South Africa, it is associated with another blue mineral of similar chemical composition, sugilite.
Rock describes an inorganic material that is an aggregate, or mixture, of minerals. Rocks are igneous, metamorphic, sedimentary or in rare cases extraterrestrial (meteorites and some tektites).
Roman Glass is actual glass that has been buried for 2,000-years in mineral-rich soil. Archeological sites located near Jerusalem serve as the main source of Roman glass, notably because Israel once served as a major glass-making center. A thin layer of patina naturally forms on the glass as minerals in the soil react with the glass. The natural process of oxidation creates the various shades of blues and greens on the surface. As the coloration depends on the mineral condition to which the glass is exposed, each piece is unique.
Rosalinda is found outside Tambo Colorado, Peru, and was introduced to the market in 2011. The white areas of the stone are made up of marialite which is a variety of scapolite. The pink inclusions are the mineral Piemontite which is a member of the epidote group.
Rose quartz is the pink variety of quartz. Rarely transparent, facet grade gems will usually display a beautiful misty appearance. This gem can be found in large sizes, and is often carved into ornaments and figurines.
One of the most desirable of all tourmaline varieties, rubellite is the pink to red variety of elbaite tourmaline, but crystals may also include brownish, orangey or purplish hues. Stones that exhibit pure red or slightly purplish red color are considered the most valuable. With the exception of ruby and red spinel, rubellite is the only other gem known to occur in such a rich, dark red color. Incredibly scarce, with 'eye clean' material even rarer, rubellite is one of those special gems that demands a place in your gemstone collection!
The sole birthstone for July, ruby is the brightest and boldest of all birthstones. Called ratnaraj, meaning the "King of Gems" by ancient Hindus, ruby's association with the blood of life has earned it powerful praise and high esteem since antiquity. Ruby is mentioned at least four times in the Bible, always in reference to beauty and wisdom. Its passionate red color makes ruby an ideal choice for a romantic gift that comes with a rich legacy.
Ruby in zoisite is a translucent to opaque rock composed of ruby crystals, green zoisite and black hornblende. The official name for this gem is "anyolite," from the Masai word anyoli, meaning "green." This gem is usually used as an ornamental stone due to its stunning color contrasts.
Rudraksha Seeds are used as a prayer beads in Hinduism. Rudraksha is loosely translated from Sanskrit as "Lord Rudra's teardrops".
Gemstones are usually treasured for their crystalline varieties that contain little or no inclusions. Some varieties, however, are favored because of their unique inclusions. One such variety is rutilated quartz. Striking in appearance, the thin, elongated red to golden rutile needles may form parallel to one another or have random distribution throughout the quartz. On rare occasions, needles may radiate in six different directions, creating a star-like pattern. Specimens exhibiting this pattern are the most highly prized of all.
The name rutile comes from the Latin rutilas, meaning "reddish," as this mineral is usually red to golden in color. Rutile forms in a wide array of habits. It is often seen as an inclusion within gems either as large needles that make bold patterns, or as fine, microscopic fibers that cause chatoyancy and asterism in gems. It is highly refractive and is occasionally found in facetable sizes.
The term saltwater pearl refers to the pearls that are harvested in marine environments such as bays, gulfs, and seas. South Sea, Tahitian, Akoya, and Sea of Cortez Pearls are the best known cultured saltwater varieties. Cultured saltwater pearls are more expensive than freshwater varieties.
Sandstone is a sedimentary rock composed of sand-sized grains. Often banded in appearance, sandstone is one of the most common types of sedimentary rock and is found throughout the world. It is often mined for use as a construction material or as a raw material used in manufacturing. This stone can be cut, polished and carved for a variety of both practical and ornamental purposes.
Sanidine is a potassium-rich feldspar which is related to amazonite (microcline) and orthoclase by its chemistry. Sanidine gems that display adularescence, a mystical internal glow, are called moonstone. Colorless to yellow and pale brown gems have been found in Germany, Mexico, and Madagascar.
September's birthstone has come a long way since the days when any and every blue stone was called a sapphire. Though its fame is shared with its "Big Three" counterparts ruby and emerald, sapphire has enjoyed a long run as one of the world's most beloved gemstones, earning itself a place of honor in crown jewels, royal accessories, museums, and even in modern royal engagement rings. Lest sapphire get too haughty, it has common uses as well. The rough polishing material on emery boards is made up of lower-quality corundum grains, strengthened with hematite, magnetite and quartz.
Sapphirine was so named because of its resemblance in color to blue sapphire, even though the two minerals have completely different chemical, optical and physical properties. Sapphirine is very rare, with small gems only faceted for collectors. This gem is know for blue color, but occasionally forms in a red-orange variety.
Sard is a translucent chalcedony that is light to dark reddish-brown. It is formed from the deposition of silica at low temperatures from silica-rich waters percolating through cracks and fissures in other rocks. Sard is darker and browner in tone than carnelian.
Scapolite's name is derived from Greek words meaning "rod" or "shaft" and "stone," which describes the shape of its crystals. Originally discovered in 1913 in the Mogok stone tract of upper Burma, scapolite has been found in many locations. However, it is typically found only in small pockets, leading to its status of rarity in the gemstone world. Scapolite is a mineral group of colorless, or translucent pink, orange, yellow, green, blue, violet or purple gemstones.
Scheelite, named for Swedish chemist C.W. Scheele is a calcium tungstate, a major source of tungsten. Most scheelite is fluorescent and ranges from blue to white in color. Spectacular, transparent crystals come from Austria, Italy, Brazil, Rwanda, and Colorado. Scheelite crystals often have high luster and fire that is almost adamantine.
Schorl is the most common species of tourmaline, however, it is not as commonly faceted as its brightly colored brothers and sisters because of its black color. Well-formed schorl crystals make striking mineral specimens and long, thin schorl crystals are frequently found in quartz, called "tourmalinated quartz."
Scolecite is a fascinating zeolite mineral. Its name is derived from the Greek word, skolex, meaning worm because under a flame, scolecite curls up like a worm. It shares the unusual properties of piezoelectricity and pyroelectricity with other gem minerals like tourmaline.
Selenite is the name for transparent, colorless to near colorless crystals of gypsum, a hydrous calcium sulfate that is found in a number of forms. The name "selenite" comes from the Greek word selene, meaning "moon", no doubt in reference to the gem's white glow. Gypsum, in all varieties, is very soft and has perfect cleavage so it should be handled with care.
Nicknamed the "dragon stone," septaria has unique mineral patterns that resemble tree branches. Specimens are usually in the form of sliced nodules ranging from an inch in diameter to more than three feet across. They are estimated to have formed between 50 and 70 million years ago after periodic volcanic eruptions killed small sea life. The shells and carcasses of these creatures sank to the sea bed, where sediments accumulated around them to form nodules or balls of mud. When the waters eventually receded, the mud balls dried out and began to shrink and crack into the beautiful patterns that you see inside the septarian nodules.
Seraphinite was named after Seraphim, the highest rank of angels in the Bible, due to the feather-like appearance of its chatoyant fibers. The stone usually has a dark green to gray color with silvery shimmer caused by mica inclusions. This unique, somewhat mystic-looking gem is often used for carvings, decorative pieces and cut as cabochons.
Serpentine is well known to the world's mineralogists and gemologists, but is much less familiar to the general public. The marbled look of this green stone makes it ideal as an ornamental material, and it has been carved into a wide array of decorative objects throughout history. Although serpentine has a similar appearance to jade, it is a different, unrelated series of minerals.
Shanseres® is a new variety of Diopside offered for the first time at Jewelry Television in June of 2007. This type of Diopside is not treated, the color is natural, and unlike our very popular gem Chrome Diopside, Shanseres® has no presence of chromium. The lack of chromium is about the only difference between chrome diopside and Shanseres®.
Shattuckite is an extremely rare cuprian mineral that is found mixed most commonly with quartz. Its name is derived from a find in the Shattuck Mine in Bisbee, Arizona. Shattuckite comes in pale to striking blue shades.
Shells are the protective outer coverings from various animals. Most of the shell used in jewelry comes from helmet conchs, mollusks, black-lipped oysters, and abalone. The earliest known shell jewelry dates to 82,000 years ago from a site in Morocco. It is thought that shell’s first use as an ornamental material was a byproduct of the search for food. Shell is best known for its use in mother-of-pearl buttons and knife handles. Cameo carvers take advantage of the different colored layers of shell to create images of beautiful women and classical scenes.
“Shell pearls” are imitation pearls. A mother of pearl bead nucleus is coated to resemble Tahitian, South Sea, or freshwater cultured pearls. They are an affordable alternative to their more expensive counterparts.
Siderite was discovered in 1845 and derives its name from the Greek sideros (iron). Siderite has perfect cleavage in three directions and comes in a wide variety of crystal habits and colors.
Beautiful and rare, sillimanite is named for the famous American geologist Benjamin Silliman. It was relatively unknown until a substantial find was discovered in Orissa, India, in the 1990's. Sillimanite is not only scarce, but it also difficult for miners to identify and is problematic for cutters. These three attributes ensure that sillimanite remains a true exotic gemstone. Sillimanite ranges from colorless to white, brown, yellow, blue, and green in color and consists of compact fibrous material that have a silky luster. A polymorph of kyanite and andalusite, sillimanite makes an exciting addition to any gemstone collection.
Sinhalite is named after its discovery location, Sri Lanka, using its Sanskrit name, Sinhala. This rare gemstone was, until recently, only found in Sri Lanka, but is now mined in Tanzania, Madagascar and Burma. Often occurring in green to brown to brownish black hues, it was once mistakenly believed to be a variety of olivine.
Smithsonite is named for James Smithson, the English founder of the Smithsonian Institution who first identified the mineral. Although it rarely forms crystals, smithsonite is most commonly found as botryoidal or stalactitic masses or as honeycombed aggregates. A member of the calcite group of minerals, smithsonite is prized for its variety of crystal forms. Smithsonite comes in a wide variety of colors depending on the impurities present. The presence of copper gives smithsonite its green to blue coloring. Trace amounts of cobalt are responsible for pink to purple hues while cadmium makes smithsonite yellow, and iron gives it a brown to reddish-brown color.
Smoky quartz is an earth-toned transparent quartz that comes in a variety of shades, including cognac. Smoky quartz gets its rich warm colors from color centers when aluminum replaces silica in the crystal lattice of the quartz after exposure to gamma rays. A popular ornamental stone, it is often carved into figurines and ornate statues, but makes quite a statement when faceted into stunning gemstones.
Soapstone, also known as steatite, refers to compact masses of talc and other minerals known for their soapy or greasy texture. Due to its softness, it has been used since ancient times for carvings, ornaments and utensils.
Sodalite is a mineral used most often for carvings and some types of jewelry. Known for its rich, royal blue hues, sodalite is found in limited areas of the world. Frequently mottled with white veins of calcite, sodalite resembles lapis lazuli in appearance and has been mistaken for it at times. It can occur not only as blue, but also in crystals of gray, yellow, green or pink color.
South Sea Pearl
Highly coveted South Sea pearls are often described as the pinnacle of cultured pearls--they're certainly among the most rare and expensive available. Primarily farmed in the pristine waters off Australia, the Philippines, and Indonesia, South Sea pearls are generally much larger than other pearl types, ranging from nine to 20 millimeters, and have a unique luster due to their nacre coating. As there are two varieties of this oyster, a gold-lipped and silver-lipped, pearls can be both white to silver and golden.
Spectrolite is the tradename for the phenomenal labradorite variety from Finland. Spectrolite is known for its colorful and striking iridescence that shows blue, green, yellow, orange, and red colors. The colors are often compared to the northern lights seen in the Finnish night sky. Depending on the account, Spectrolite was discovered in either the winter of 1939-1940 or 1941 when Finland was building border fortifications during the Finnish-Russian campaign in WWII. Spectrolite mining started after the war. In 1973 a workshop was established in the Ylämaa area, Lappeenranta, South Karelia, Finland for cutting and polishing the gemstone.
While it was once just a collector's gem, spessartine, an orange variety of garnet, made its move into the mainstream during the 1990s when new deposits were discovered in Africa. Like most garnets, spessartine is typically untreated, so the beautiful color and clarity that you see in them is just as nature created it. Spessartine garnet is named after its first discovery in Spessart, Bavaria, in the mid 1800's.
With greater dispersion than diamond, sphalerite is an intriguing, yet challenging, gem. Known primarily to collectors for its lack of hardness, sphalerite can try the patience of even the most highly skilled lapidaries who dare to fashion it into a finished gem. Not only is it extremely soft, it also has perfect cleavage in six directions, making it extremely difficult to cut and polish! Add in the fact that it's a brittle gem, and you have an idea of the challenge that awaits its potential cutter. When a talented lapidary can complete the task of fashioning a gem, the results are more than worth the lapidary's efforts!
A brilliantly transparent gem, sphene has fire greater than that of diamond! This gem is named from the Greek word for "wedge," as its crystals are typically wedge shaped, but may be referred to by its mineral name, titanite. On rare instances, sphene may be brown or black in color, but is mainly found in a range of green to yellowish green colors. Another characteristic sphene possesses is birefringence, or double refraction, meaning that light splits into two rays as it passes through the gem. As a result, the back facets appear as double images, giving the gem a soft, hazy appearance, similar to the doubling seen in zircon.
Naturally dazzling spinel has graced the pages of history and many royal crowns due to its resemblance to ruby. Today, however, spinel stands on its own as a remarkable gem. Spinel comes in a wide range of stunning hues and can also exhibit optical phenomena like asterism and color-change. It is generally underappreciated compared to other colored stones, lending itself to more affordable prices, but this gem, said in Burma to be polished by the spirits, has a beauty that is difficult to ignore.
Spodumene is the name of a mineral species that includes two very special gems varieties: kunzite and hiddenite. Spodumene is named from the Greek spodoumenos, meaning "burnt to ash," which alludes to the ashy color of many specimens. A member of the pyroxene group, spodumene belongs to a class of minerals called silicates and it is one of a small number of minerals that contain lithium. Spodumene also occurs in many other shades of colors, all pale but very clear and brilliant. These varieties are given color descriptor names; for example, lemon spodumene.
Stalactites and stalagmites are types of speleothems or cave formations that are formed by slow deposition of minerals by dripping water. These cave formations are formed when rainwater combines with carbon dioxide to create carbonic acid which then permeates carbonate rocks in the subsurface. The acidic water dissolves carbonate material as it filters through the rock. The dissolved carbonate is carried to caves in the subsurface where the carbon dioxide is released and the water evaporates leaving calcite formations to build up over the millennia. Formations hanging from the cave roof are called stalactites while those that build up from the cave floor are called stalagmites. Sometimes the two will join to form a column. Other carbonates such as azurite and malachite, silicates such as opal and chalcedony, limonite, some sulfides, and other minerals can also be deposited. Stalactites are very fragile, and many US states and countries have laws that prohibit collecting them from caves. Some gem material stalactites have been collected as byproducts during mining. Chrysocolla stalactites have been found in the Pearl Handle Pit, in the Ray Mine, Arizona. The Morenci Mine, also in Arizona, has produced goethite and azurite stalactites. Morocco has produced azurmalachite specimens. Large malachite specimens have come from the L'Etoile du Congo Mine, sometimes called the Star of the Congo Mine, in the Democratic Republic of Congo. Vanadinite stalactites have been found in the Mibladen Mining District, Morocco.
The name staurolite comes from the Greek word stauros, meaning cross. Staurolite is prized for its twinned crystals that intersect at 60- or 90-degree angles forming x-like or perpendicular crosses. Specimens exhibiting these forms are highly prized by collectors. Sometimes referred to respectively as St. Andrew's and Greek crosses, as well as lucky cross, fairy stone or fairy cross, legend says the crystal crosses were created by the tears of fairies who could not help but cry when they heard of Christ's crucifixion. Staurolite is a metamorphic mineral that ranges from translucent to opaque in appearance and facetable gems are very rare.
Stibnite forms as delicate, elongated crystals with metallic luster that are lead-gray in color. It is an important source of antimony. In ancient times it was ground into a powder and mixed with fat to be used as the eye makeup called kohl. It was also a component in ancient flash powder.
Stilbite is named from a Greek term meaning "to glitter" due to the pearly luster of the mineral. A member of the zeolite group, stilbite is often white, peach, pinkish, yellow or brown in color. Stilbite is further classified based on its sodium and calcium content. Stilbite is rarely faceted, but its attractive crystals make it highly collectable as mineral specimens
As its name implies, strontium titanate, also known as Fabulite, is an oxide combination of strontium and titanium. It was originally created as a diamond simulant. Fabulite gems are easy to distinguish from diamonds, as their high dispersion and considerably lower hardness are dead giveaways. For the most part, this jewel fell into obscurity when the hugely popular cubic zirconia (CZ) entered the market in the 1970's. While strontium titanate was originally believed to only be available via laboratory creation, it was discovered in natural form in the 1980's in Siberia and named tausonite in honor of a Russian geochemist.
Sugilite belongs to a class of minerals known as silicates and is a member of the milarite group. A relatively recent addition to the realm of gemstones, sugilite was discovered in 1944 by a Japanese geologist, Ken-ichi Sugi. The mineral is named in his honor. The original find was a yellowish brown variety that was of no interest to the jewelry industry. It was not until 1979 that the first massive aggregates, exhibiting a rich purple color, were discovered in a South African manganese mine. This material was attractive and gained the attention of the gemstone industry. It is predominantly found in the form of cabochons of various shapes and sizes, but has also been used as a component in intarsia jewelry. It is sometimes carved into decorative objects and fashioned into beads.
A gem known since ancient times, sunstone is a type of feldspar formed and crystallized in lava flows. Radiating with the power of eternal light, sunstone has been reportedly found in the tombs of Viking sailors who believed it would aid in their journey through both life and the afterlife. A distinguishing feature of sunstone is its metallic schiller, which rolls across the stone's surface. The effect is due to the presence of small plate-like inclusions of minerals such as hematite or native copper. These inclusions interfere with the passage of light, causing it to scatter. If the inclusions are larger and visible to the eye, they create glittery star-like reflections that gemologists refer to as aventurescence.
Szaibelyite is a basic magnesium borate mineral named after Stephen Szaibely (Sjájbely). It is pale yellow to white and has a fibrous structure.
A rare and beautiful mineral, taaffeite is a lilac to mauve, brown to red, bluish green crystal that may be transparent to translucent in appearance. Interestingly enough, this gem was first discovered as a faceted gemstone that was thought to be spinel. Eventually, the mineral was found in Sri Lanka.
Tahitian pearls, grown around Tahiti and French Polynesia, display a shimmering orient or overtone that is green, blue, pink or violet in color. These orient colors are in striking contrast to their silver to black body color and are sometimes given specific names (e.g., deep green is called fly wing; peacock is used for the combination of green and pink; eggplant is a dark toned body color combined with pink).
Tantalite’s name alludes to the tantalum that makes up a large part of its chemical formula. Tantalite has numerous industrial uses but is only of interest for its mineral specimens and for exotic gemstone collectors. The color ranges from brownish to black sometimes with a red component.
Henry Platt, former president of Tiffany & Co., described tanzanite's discovery in 1967 as the most important gemstone find in 2000 years! A single 5-mile strip of land in Tanzania remains the only commercially viable source of this stone that has become one of the world's most sought-after and admired gems. Tanzanite is a relatively new gemstone in the world of gemology and jewelry. Though its history is brief, it is no less illustrious than many ancient gems. Tanzanite is a single-source gemstone that is a thousand times rarer than diamond, and it is only gaining popularity.
Tektites are unique in that they form when a meteorite melts the surface of the Earth where contact is made. The heat of impact results in molten rock and sand being tossed into the air, raining back down as a natural glass. Tektites are named for the locations where they are found, i.e., moldavite is from the Moldau river area of the Czech Republic. Common colors of this natural glass are yellow, green, gray to black, and colorless.
Thulite is the translucent to opaque pink variety of zoisite, which is often mottled or streaked with gray or white quartz. The name thulite is derived from its discovery location, Norway, which was once called Thule. This gem is also called rosaline. Thulite is often cut en cabochon for jewelry manufacture or carved into ornaments.
Tiger iron is a rock that is made up of tiger's eye quartz, black hematite and red jasper. These minerals create contrasting bands of color for a truly unique look popularly used for many sorts of ornamentation and decoration.
Tiger's eye is a unique and mysterious member of the quartz family. It ranges in color from rich, golden yellow to bronze and brown. Best seen when gems are cut en cabochon, tiger's eye displays an optical phenomenon known as chatoyancy. Unlike other chatoyant gems, tiger’s eye quartz is made up of quartz with intergrown fibers of amphibole that were altered to golden or rusty-brown limonite. When light hits the surface of this gem, a silky, wavy shimmer moves across the surface of the stone resembling the eye of a tiger. A related variety of quartz called hawk’s eye is blue due to unaltered inclusions of crocidolite.
Titanite gets its name from the titanium in its chemical makeup. Gem quality material is known as sphene. The crystals form as wedge shapes and twinning is common. The color can range from yellow to red, brown, brownish, or yellowish green to green, and black. Specimens can have adamantine luster and high dispersion. Titanite has a high birefringence.
Topaz can be both very common (when clear, or in certain colors like brown, which can turn blue when treated) and very rare (when found in natural beautiful colors rare to the species, like pink and red). Topaz's popularity stems from the gem's good wearability and affordability. Topaz is also often altered with special surface treatments to give it unusual colors and iridescent effects, like mystic, ocean, kiwi, and orchid topaz. Topaz is also a popular birthstone, as blue topaz is December's primary birthstone and yellow topaz is a birthstone for November.
Topazolite is an Andradite Garnet that is yellow or brownish in color. It has a similar appearance to Topaz, and this resemblance inspired its name.
Mother Nature must have been in a whimsical, artistic mood when she created tourmalinated quartz. These crystals are usually colorless rock crystal with long, slender tourmaline inclusions, usually black in color. A relative unknown to the general public, this gem is truly a marvel! The inclusions are always one-of-a-kind, making a beautiful display in a gem collection or jewelry pieces.
Once proposed to be the national gemstone of the United States, tourmaline is found all over the world and in a variety of colors. Tourmaline is the most colorful of all gemstones because, according to an ancient Egyptian legend, it passed through a rainbow on its journey to Earth and brought all of the colors of the rainbow with it. Tourmaline is a mineral group comprised of multiple species of complex borosilicates. Lovingly referred to by mineralogists as the garbage can mineral, its crystal structure allows for the incorporation of a wide range of elements, many of which cause the stunning color varieties and spectacular zoning of tourmaline, including copper, manganese, iron, and titanium. Major tourmaline species include liddicoatite, dravite, uvite, schorl, and elbaite.
Deriving its name from a locality in the Swiss Alps, tremolite is a member of the amphibole group, a complex series of silicate minerals. It forms in thin, parallel fibers, sometimes producing a distinct cat's eye effect when cut in cabochons. Tremolite comes in a variety of colors ranging from white, brown, colorless, gray, light green, light yellow and pink-violet. This gem sometimes occurs as fine, needle-like inclusions in emerald and quartz.
Trilobites are remarkable, hard-shelled creatures that lived some 400 to 500 million years ago in Earth's ancient seas. Trilobites represent the single most diverse class of extinct organisms. Throughout the 270 million years they inhabited the oceans, they continued to evolve into various species, leading to a great deal of diversity in their size, form and function. This means there is a wide variety of trilobite fossils to collect! One of the most appealing factors about trilobite fossils is that you can hold and examine an entire fossil animal as you turn it about in your hand.
The term triphane originated as another name for spodumene, but more recently has been used in reference to colorless to light yellow transparent spodumene. Triphane's name is derived from a Greek term meaning 'three aspects', due to its distinctive trichroism.
Triplite is named for its three cleavage planes that are oriented at right angles to each other. The structure of this stone, combined with its brittle nature, makes faceting very difficult. Successfully faceted triplite gems are coveted by collectors.
Tsavorite is one of two green varieties of garnet, though arguably the more important of the two. Especially in smaller sizes, tsavorite creates competition for emerald because it is less included, rarely treated and more durable. Like some emerald and green tourmaline, tsavorite garnet owes its green hues to the presence of vanadium and chromium. First discovered in Tanzania in 1967 and a few years later in Kenya, tsavorite's name pays homage to the nearby Tsavo National Park.
Tugtupite gets its unique name from the location of its discovery in southwest Greenland. This semi-transparent to opaque mineral species is usually pink to red and often mottled with white, gray or black. Nicknamed the "Reindeer Stone," tugtupite is tenebrescent; when stored in darkness, the gem's color will fade, but returns immediately upon exposure to daylight. Among collectors, tugtupite is also prized for its luminescent properties: strong fluorescence and less commonly, phosphorescence, when the gem continues to fluoresce even after the ultraviolet light source has been removed.
December's birthstone, turquoise was among the first gemstones ever mined. Stunning sky blues to stimulating sea greens have made turquoise one of the most popular color trends in jewelry history. Copper gives turquoise its range of blue hues while iron is responsible for its green colors. Treasured since the days of ancient Egypt, and the thousands of years since, turquoise is said to bring good fortune and happiness to those who wear it.
Also called the "TV rock" or "television stone," ulexite is known for its unusual optical characteristics, notably its ability to transmit images through its natural fibers. A piece of writing placed underneath the stone appears on the surface of the stone! Ulexite was named for German chemist G. L. Ulex, who first correctly analyzed the species in 1850. Most specimens are milky and very poor quality, but those stones that are cut as cabochons often display a strong cat's eye effect.
Umbalite is also known as Malaya (Malaia) garnet. Umbalite is a relatively new member of the garnet group. First noticed in the 1960s, it was mixed in with parcels of rhodolite garnets from the Umba River Valley in East Africa. Many buyers rejected the material, so local miners and dealers gave it the Swahili name of “Malaya”, which translates to “out of the family”. Testing eventually confirmed that this new gem was a mixture of pyrope and spessartite garnet. Its lively color ranges from light to dark pink, red, and yellowish orange. After overcoming initial objections, it carved a small, but dedicated niche in the market in the 1980s, particularly in the United States. Today, umbalite is one of the more expensive garnets, and its only known sources are Kenya and Tanzania.
Unakite is a type of granitic rock that features mottled patterns of green epidote, white to gray quartz, and pink feldspar, occasionally with black veining. This compact, hard gem is most often seen as cabochon gems, carvings and beads or sold as tumbled rough.
Named after Niels Viggo Ussing, professor of Mineralogy at the University of Copenhagen, this rare silicate mineral can be found in only a few locations worldwide including Greenland and northern Russia. It typically has a massive habit and can be light pink, lilac-blue, and in rare cases dark violet-red.
Uvarovite is a highly desirable, yet widely unknown garnet species. Discovered in the 1830's in Russia, it was named in honor of Count Sergey S. Uvarov, a 19th century Russian statesman, scholar and avid mineral collector. Especially prized by collectors, uvarovite is hard to find anywhere, especially in sizes greater than 0.25 carats. Uvarovite ranges in color from medium to dark green and is best known for its granular, drusy masses which reveal well-formed dodecahedral or trapezohedral crystals under magnification.
Vanadinite derives its name from the vanadium contained within its chemical formula. Well-formed mineral specimens are prized by collectors. It comes in red to brown, orange, and yellow. It rarely appears colorless or white. Fine mineral specimens come from Morocco and Namibia.
Variscite is a phosphate mineral that is translucent to opaque with green to bluish green coloring that is often mottled or veined. This gem is commonly cut en cabochon or used for carvings. With a similar appearance to green turquoise, variscite is named for its location of first discovery in Germany. When mined in Utah, some prefer to call it Utahlite.
The Venetian glass industry dates back over 1,500 years. A 1291 Venetian law relocated all glass making to the island of Murano. The stated reason for the law was to prevent fire from destroying the wooden buildings of Venice. Speculation behind the true nature of the law was to protect the design techniques and innovations of the glass artisans from being stolen and taken to other regions. In the early 1800’s the political climate forced the Venetian glass industry into decline. In the Mid 1850’s a resurgence of glassmaking in Venice commenced. The beginning of the 20th century glass makers focused on reproducing classical styles and the rediscovery of the lost techniques of early Venetian artisans. Modern glass artisans are innovating new techniques and inspiring creative designs to establish Venice as the glass blowing capital of the World.
Verdelite refers to green elbaite tourmaline that does not contain chromium. Although green is a common color of tourmaline, not all greens are valued equally. Verdelite gems come in varying shades of green; some so saturated that direct light is necessary to see the body color. From lush grass-green to electric yellow-green to olive, and even bluish green, there is a verdelite gem to fit all tastes.
Vesuvianite, also known as Idocrase after its discovery at Mount Vesuvius, has crystals that are prismatic and glassy. It is usually green or chartreuse in color, but may be found in yellow to brown, yellow-green, red, black, blue or purple hues.
Violane is a manganese-rich, coarse variety of diopside cabbed for ornamental use or carved for decorative purposes. Colors range from light blue to deep violet. The main source is Saint-Marcel, in the Aosta Valley, Italy. Other localities include Greece and the United States (California).
Wavellite was discovered in 1805 at High Down, Filleigh, Devon, England. It was named after a local doctor William Wavell M.D. who brought it to the attention of the mineralogical community. It is translucent and can be found in blue, green, yellow, and white colors. Specimens can be stalactitic or the crystals can radiate from the center creating a spherical structure. Many notable specimens are found from the Ouachita Mountains in Mount Ida, Arkansas.
Whewellite is an unusual mineral because it is a naturally occurring rare organic substance with a definitive chemical formula. Minerals are traditionally inorganic, but whewellite forms crystals with the aid of oxalic acid from coal or organic debris within sedimentary rocks. This mineral is seldom seen by collectors, and almost never as a faceted gem.
Willemite was discovered in 1830 and named after William I, King of the Netherlands. This stone has remarkable luminescent properties. Some specimens glow under an ultraviolet source and continue to glow after the UV light has been removed, a phenomenon called phosphorescence. Specimens that are faceted make beautiful gemstones in blue, yellow, green and brown colors.
This gem was named in 1790 for William Withering, the English physician and naturalist that first described the mineral. This mineral is rarely faceted due to the scarcity of gem-quality rough and also because witherite dust (a primary component of rat poison) is toxic if inhaled. Cut gems are very small and are typically white or colorless.
Wood has been used for ornamentation for thousands of years. It can be carved to make beads or formed into bangles and pendants. It can be used in its natural state for an organic look or dyed to add bright pops of color. The light weight and versatility of wood has made it a popular material of jewelry designers.
Known for its striking orange, yellow, and red hues, nice luster, and unique crystal habits, wulfenite is a lead molybdate that is found in the oxidation zone of lead-ore deposits. Wulfenite typically forms thin, tabular crystals. Finding a crystal thick enough to fashion into a gem is challenging.
Wurtzite is named after French chemist Charles Adolphe Wurtz. It was first described in 1861 after it was discovered in the San José Mine, Oruro City, Cercado Province, Oruro Department, Bolivia. It can be dark reddish brown, yellow to dark brown, to brownish black with a resinous or submetallic luster.
Xaxim is a type of petrified tree fern from a period of time even before the dinosaurs roamed the earth. Estimated to be some 270 million years old, these fossilized specimens offer an exciting window into the past. Similar in appearance to the palm tree, xaxim trees can still be found growing in Brazil today. However, they grow very slowly, averaging about 3 inches every 10 years. Featuring all natural color with no enhancement, xaxim is prized by fossil collectors across the globe.
Yttrium aluminum garnet (YAG) is a lab created gem first developed in the 1950's. Its primary application was in optics and laser technology, but it turned out to be a convincing diamond simulant. Although YAG has garnet in its name, it is not related to garnet; it is an artificial gemstone with no natural counterpart.
Zandrite® is the brand name for a man-made stone that is highly photochromic. It is a chemically doped variety of glass, whose name is an allusion to alexandrite, an expensive naturally occurring color-change variety of chrysoberyl. Zandrite® is specially formulated by combining rare earth elements (like neodymium, lanthanum, and cerium) to create a stunning color change property. A scientist was the first to create, then realize the potential of this stunning gem (completely by accident).
The majority of gem-quality zincite in the market is the byproduct of Polish metal refineries where the material crystallized in the factory smokestacks and was then harvested during cleaning. Zincite can also be found naturally in a few localities, most notably associated with metamorphosed zinc ore bodies in Sterling, New Jersey, though the crystals are rarely of gem quality.
Radiant zircon is the oldest known gemstone, with some crystals dating back 4 billion years, but also perhaps the most misunderstood. Unfortunately, due to the similarity of zircon's name to the lab created diamond simulant cubic zirconia, many people don't realize that zircon is a beautiful, naturally occurring stone with its own merits. Thanks to its tremendous fire and dispersion, it has been considered a less-expensive stand-in for diamond for many years, although zircon gives us many reasons to sing its praises and appreciate it in its own light.
Zoisite is a mineral species in the epidote group. The most celebrated variety is its blue to violet occurrence, tanzanite, but other zoisite colors include red, pink (thulite), green and purple. Discovered in the early 19th century, zoisite was named after Baron von Zois, an Austrian scientist and mineral collector.