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).