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.