Adamantine - "Diamond-like luster and hardness," derived from the Greek word Adamas (invincible) for diamonds.
Adularescence - The billowing shimmer of light floating across the surface of a moonstone.
Agate - A quartz crystal and a sub-variety of chalcedony found in a wide range of pale colors including green, yellow, red, reddish-brown, white and bluish white. Measuring a 6.5-7 on Mohs' scale of hardness, agate has a waxy or dull luster. Found in parts of southern Brazil, northern Uruguay, Australia, China, India, the Caucasus, Madagascar, Mexico, Mongolia, Namibia, Wyoming, and Montana.
Alexandrite - A highly prized variety of chrysoberyl that appears grassy green in daylight, and in tungsten light appears raspberry red. On Mohs' scale of hardness, alexandrite is 8.5. It has a strong vitreous luster and can be found in Sri Lanka, Zimbabwe, and Brazil.
Almandite/Almandine - A variety of garnet usually found in a violet red hue. Measuring 7.5 on Mohs' scale of hardness, almandite has a vitreous luster and is found in Brazil, India, Madagascar, Sri Lanka and the United States.
Amber - A fossilized, organic mixture of pine resins, acids and volatile oils that comes from the tree sap of the pine tree. Predominantly found in yellow and brown colors, amber measures 2-2.5 on Mohs' scale of hardness and has a vitreous luster and a resinous luster when polished. Amber is found in Russia, Sicily/Italy, Rumania, Burma, China, the Dominican Republic, Japan, Canada, Mexico, Alaska and New Jersey.
Amethyst - The most highly valued gemstone in the quartz family and found in a range of colors from violet to pale red-violet. On Mohs' scale of hardness, amethyst is 7 and it’s found in Brazil, Madagascar, Zambia, Uruguay, Burma, India, Canada, Mexico, Namibia, Russia, Sri Lanka and Arizona
Ametrine - A quartz crystal that contains amethyst and citrine measuring 7 on Moh's scale of hardness. Ametrine is primarily found in Bolivia.
Amorphous - Amorphous is an adjective meaning shapeless or lacking crystal structure (such as Amber).
Andalusite - A naturally occurring pleochroic gemstone. As the stone is rotated, different colors and different intensities of colors can appear including olive green, rich reddish brown or grayish green. On Mohs' scale of hardness, andalusite is 7-7.5. It has a vitreous or mat luster and primary sources include Australia, Brazil, Canada, Russia, Spain, Sri Lanka and the United States.
Andradite - A species of gemstones within the garnet family that includes several significant gem varieties such as demantoid, melanite, and topazolite. On Mohs' scale of hardness, it is 3.7 – 4.1.
Apatite - A naturally occurring beautiful gemstone, while known for its green hues, apatite can actually be found in a wide variety of colors from colorless to pink, yellow, blue and violet. On Mohs' scale of hardness, apatite is a soft 5. It has a vitreous luster and is found in Burma, Brazil, India, Kenya, Madagascar, Mexico, Norway, Sri Lanka, South Africa and the United States.
Aquamarine - A member of the beryl family, is known for its clear sky-blue color but is also found in a range of dark blues to blue-greens. Measuring a 7.5-8 on Mohs' scale of hardness, aquamarine is found in Brazil, Russia, Australia, Burma, China, India, Kenya, Madagascar, Mozambique, Namibia, Nigeria, Zambia, Zimbabwe and the United States.
Aventurine Feldspar - Another name for Sunstone.
Baguette - These small, rectangular stones are used as accessories to larger stones and are normally step cut.
Baroque Pearls - These distinctive pearls are found in unusual, intriguing shapes that lend themselves to uniquely designed pieces of jewelry.
Bead - A gemstone, usually round, with a hole pierced through it so that it can be strung.
Beryl - A silicate mineral with several varieties of gemstones including well known gems like emerald, aquamarine, as well as more exotic gems like goshenite, morganite. These various gemstones come in a wide variety of colors ranging from greens, blues, yellows, reds, pinks and colorless. On Mohs' scale of hardness, beryl is 7.5-8.
Black Onyx - Dyed chalcedony. According to some experts, black onyx is produced by boiling slabs of grayish chalcedony in a solution of sugar which enters the pores between the submicron crystallites.
Blister Pearl - A pearl that forms attached to the shell.
Bloodstone - From the chalcedony family, this green stone has red spots that look like blood.
Boulder Opal - A member of the opal family with a dark base surface and an exciting play of color. On Mohs' scale of hardness, boulder opal is 1.98-2.50 and found in Australia, Brazil, Guatemala, Honduras, Indonesia, Japan, Mexico, Russia, Nevada, and Idaho.
Cabochon - A highly polished, unfaceted gemstone cut into the shape of a small dome.
Calcium carbonate - This is one of the most common minerals on the face of the earth and is found in calcite, aragonite, and vaterite. Thousands of microscopic calcite and aragonite crystals form the layers of nacre forming a pearl.
Carnelian - A quartz crystal and a sub-variety of chalcedony found in flesh-color to reddish brown to a uniform red. On Mohs' scale of hardness, it measures 6.5-7 and has a waxy or dull luster. Found in Brazil, India, and Uruguay.
Chalcedony - A family of fine-grained quartz crystals including agate, chrysoprase, bloodstone, jasper, carnelian, moss agate, onyx and sard with a hardness level o f6.5-7. In their natural state, they have a waxy or dull luster. For source information, see specific stones.
Chrysoberyl - A mineral that produces gemstones ranging from golden-yellow to green-yellow, green, brownish and red. On Mohs' scale of hardness, it is 8.5 and is found in Brazil, Sri Lanka, Burma, Russia, Zimbabwe and the United States.
Chrysoberyl Cat's Eye - A highly prized gemstone in the chrysoberyl family. The shortened term "cat's eye" always refers to chrysoberyl cat's eye. When cut in a cabochon or dome style, it displays fine, parallel lines of moving light rays that appear similar to the pupil of a cat. On Mohs' scale of hardness, it is fairly hard at 8.5. Primary sources include Sri Lanka and Brazil as well as China, India, and Zimbabwe.
Chrysoprase - The name for apple-green chalcedony.
Citrine - A quartz crystal that may be found in a range of yellows from light yellow to dark yellow and golden brown. On Mohs' scale of hardness, citrine is 7. Sources include Brazil, Madagascar, the United States, Argentina, Burma, Namibia, Russia, Scotland and Spain.
Color (Diamonds) - Color (or the absence of color) is one of the most noticeable characteristics of a diamond. Color grading, using the GIA scale, ranges from D to Z, with D being colorless and Z being heavily (usually yellow) colored. Colorless stones (designated D, E, and F) command the highest prices.
Color (Gemstones) - One of the most important characteristics in appreciating gemstone. Color in gemstones is described by hue, saturation, and tone.
Color Change Gems - Color change gems change color due to changing light conditions (Alexandrite) or from different angles (Andalusite).
Colored Diamonds - Also known as fancy diamonds, this refers to all diamonds that are not white.
Corundum - A gem mineral composed of gas oxygen and light metal aluminum. The two most valuable corundum include the Ruby and the Sapphire. Due to its hardness, brilliance, and variety, some experts consider corundum to be the most important and most versatile of the gem families.
Crystal - Crystal contains a minimum of 10% lead oxide giving it an extraordinary character of brilliance.
Cubic Zirconia - A lab created diamond simulant. While Cubic Zirconia, CZ, is a transparent stone, trace elements can be added to the manufacturing process, producing a wide range of colors. CZ is harder than other gemstones except for diamond, ruby, sapphire, and chrysoberyl. Some of the most popular CZs are manufactured in Russia.
Cultured Pearl - Patented in 1916 by Kokichi Mikimoto, this is a process of cultivating pearls by artificially inserting a small irritant (like a small bead from mother-of-pearl) into an oyster or other bivalve mollusks.
Danburite - A lesser known gemstone originally discovered in Danbury, Connecticut found in colors of wine-yellow, brown and even pink. On Mohs' scale of hardness, it is 7-7.5 and has a vitreous or greasy luster. Danburite is found in Burma, Japan, Madagascar, Mexico, Russia, and Connecticut.
Demantoid - A highly valued andradite garnet that exhibits a range of greens from dull to bright emerald green and on rare occasions displays yellow. On Mohs' scale of hardness, demantoid is relatively soft at 6.5. It has an adamantine luster and sources include China, Korea, Russia, the United States, and Zaire.
Diamond - A crystallized carbon, the only gem composed of a single element. The most popular diamonds are traditionally colorless, but they can also be found in yellow and brown colors. Although much rarer, diamonds known as "fancies" also come in blue, red, pink, green, orange and black. On Mohs' scale of hardness, diamond is the world's hardest substance at 10. It has a very strong luster and primary sources include South Africa, Namibia, Australia, Botswana, Russia, Zaire, Brazil, Ghana, Angola and Central African Republic.
Diffusion Treatment - A gemstone treatments that alter the color of stones through a combination of chemical exposure and long-term heat treatment. The stones begin as colorless or extremely pale and are transformed into vibrant colors. Primarily a surface treatment, wearers should be cautious not to chip stones because the inside of the stone remains colorless. The main distinction between surface diffusion and deep diffusion is the level of penetration, but both are still essentially surface treatments.
Diopside - From the pyrozene mineral group, known for its pure green color, and may also can be found in chrome, violet-blue, black, yellow, brown and colorless. It has perfect cleavage and on Mohs' scale of hardness, diopside is 5-6. Diopside is found in Burma, Finland, India, Madagascar, Austria, Sri Lanka, South Africa and the United States.
Doublet - Assembled opals combine natural opal with other materials. A doublet contains a slice of opal glued to common opal, glass or other material. A triplet contains a slice of opal glued between a base and a crystal or a glass top. Triplets are usually less expensive than doubles, and both are less expensive than natural opal.
Emerald - The most precious member of the Beryl family that exhibits an incomparable pure green hue but can also be found in a yellowish-green hue. Emerald is 7.5-8 on Mohs' hardness scale and has a vitreous luster. This stone is found in Columbia, Zimbabwe, South Africa, Russia, Afghanistan, Australia, Ghana, India, Madagascar, Malawi, Mozambique, Namibia, Nigeria, Pakistan, Zambia, Tanzania and the United States.
Feldspar - Referring to a group of minerals that play an important role in the formation of rocks: popular varieties include moonstone and sunstone.
Fire Opal/Cherry Opal - A unique member of the opal family that displays little or no play-of-color. It is transparent to translucent and displays an orange-red to red to yellow body color. On Mohs' scale of hardness, it is 5.5-6. Sources include Australia, Brazil, Guatemala, Honduras, Indonesia, Japan, Mexico, Russia, Nevada, and Idaho.
Fluorite - Perfect for collectors and museums, fluorite (fluorspar) is a beautiful but soft stone that comes in a wide range of colors.
Freshwater Pearl - A pearl produced by a mollusk found in freshwater lakes and rivers.
Garnet - A group of colored minerals with a common crystal structure and similar (but not exact) chemical composition. The main garnet groups include pyrope, almandite, spessartite, grossularite, andradite, and uvarovite. On Mohs' scale of hardness, garnet is 6.5-7.5. This wide-ranging family of gemstones covers virtually color and is found all around the world.
Gem - Most gemstones are actually mineral crystals (except for non-mineral gems like pearls, coral, and amber). Mineral crystals form through a naturally occurring combination of chemicals, heat and/or pressure. These chemicals affect the shapes and colors of the crystals. Most mineral crystals are tiny, but a few can be cut into gemstones of rare beauty. The three chief characteristics that qualify a mineral crystal as a gemstone and help determine its value are durability, beauty, and rarity.
Golden Beryl - From the Beryl family of gemstones that exhibits a range of yellow from lemon-yellow to golden-yellow. On Mohs' scale of hardness, golden beryl is 7.5-8. It has a vitreous luster and primary sources include Brazil, Madagascar, Namibia, Nigeria, Zimbabwe and Sri Lanka.
Goshenite - Colorless gemstones from the Beryl family. It has a vitreous luster and primary sources include Massachusetts, Brazil, China, Canada, Mexico, Russia and the United States.
Igneous - Deep within the earth's inferno is a stew of molten rock and gases, called magma. As magma wells up within the earth, intense pressure forces the liquid rock toward the earth's surface. It is referred to as lava when it breaks through the surface. Lava slowly cools forming igneous rocks, and within these rocks and gas-bubble spaces, interlocking crystals grow. The minerals present, the cooling time and the environment will all play a role in the way these crystals form. Examples of gemstones found in igneous rock: diamonds, topaz, kunzite, and spinel.
Indicolite - See tourmaline.
Iolite - A gemstone with a slight variability in chemical composition between stones that exhibits a blue-to-violet range of colors and sometimes shows a brownish streak. On Mohs' scale of hardness, iolite is 7-7.5. It has a greasy luster and primary sources include Burma, Brazil, India, Madagascar, Sri Lanka and the United States.
Jade - Called the stone of heaven, jade is a hard stone that has been treasured by the Chinese for over 7,000 years. Jade comes from two different mineral species with similar appearance: nephrite and jadeite.
Jadeite - A sodium aluminum silicate that has become the most popular form of jade. Available in a variety of colors from the popular greens to orange, yellow, brown, blue, purple and black, this measures a 6.5-7 on Mohs' scale of hardness.
Jasper - A fine-grained quartz, Jasper is opaque and most commonly exhibits a brownish-red color, but it can also appear in green, yellow, brown or black. On Mohs' scale of hardness, Jasper is 6.5-7. Primary sources include Egypt, Australia, Brazil, India, Canada, Kazakhstan, Madagascar, Russia, Uruguay, and the United States.
Kunzite - A variety of the Spodumene family known for a range of pink-violet to light-violet colors but has also been identified in canary yellow, colorless, brown and green-violet. On Mohs' scale of hardness, kunzite is 6.5-7. With a vitreous luster, its sources include Brazil, Afghanistan, Burma, Madagascar, Pakistan and the United States.
Kyanite - With a similar chemical composition to andalusite and fibrolite Kyanite, it has a different crystal structure. It exhibits a range of colors including blue to colorless, blue-green and brown. On Mohs' scale of hardness, kyanite is 4-4.5. Kyanite has a vitreous luster and is found in Burma, Brazil, Kenya, Austria, Switzerland, Zimbabwe and the United States.
Labradorite - A gemstone in the feldspar family known for a brilliant play of color and exhibits lustrous metallic tints of blue, green, yellow, red, gold and purple. On Mohs' scale of hardness, labradorite is 6-6.5. It has a vitreous luster and primary sources include Canada, Australia, Madagascar, Mexico, Russia and the United States.
Lapis Lazuli - A complex composition of multiple minerals which exhibits a range of beautiful blues from lazur blue to violet to greenish blue. On Mohs' scale of hardness, lapis lazuli is 5-6. It has a vitreous and greasy luster and primary sources include Chile, Russia, Afghanistan, Angola, Burma, Canada, Pakistan, California and Colorado.
Mabe' (Or Mobe') Pearl - A dome shaped pearl that is normally round or tear shaped but also comes in a variety of shapes and sizes. The mabe is assembled by placing a small half sphere object against the shell of an oyster. After the oyster coats this irritant with nacre, the new pearl is cut from the oyster. The flat side of this new pearl is hollow and filled with epoxy and then covered with mother of pearl. Mobe pearls are a great way to get a large pearl for a lower price, but they are fragile and require special care.
Mineral Crystal - Mineral crystals form through a naturally occurring combination of chemicals, heat and/or pressure. These chemicals affect shapes and color of the crystals. Most mineral crystals are tiny, but a few can be cut into gemstones of rare beauty.
Moldavite - Part of the tekite group that exhibits a bottle-green to brown-green color. It has a vitreous luster and primary sources include Australia, Borneo, Georgia, United States, Indochina, Java, and the Philippines.
Moonstone - A gemstone in the Feldspar family that exhibits a range of colors including yellow, a pale silver sheen, a blue and even pink. On Mohs' scale of hardness, moonstone is 6-6.5. It has a vitreous luster and primary sources include Sri Lanka, Burma, Brazil, India, Madagascar and the United States.
Morganite - A gemstone in the Beryl family that exhibits a range of colors from soft pink to violet to salmon. On Mohs’ scale of hardness, morganite is 7.5-8. Primary sources include Afghanistan, Brazil, China, Madagascar, Mozambique, Namibia, Zimbabwe and the United States.
Mother of Pearl - The pearl lining of an oyster. Only mollusks that have this lining can produce pearls. This lining is also used as inlay in jewelry and other ornamental items.
Nacre - A silky substance secreted over a forming pearl. Layer after layer of nacre builds up to form what we call a pearl. When light touches the pearl, it travels through all the layers of nacre, and each tiny crystal reflects the light like miniature prisms. The end result…lustrous, breathtaking pearl.
Natural Pearl - A pearl formed through a process of a mollusk secreting nacre around an irritant that enters the shell naturally without artificial insertion. (See pearl.)
Nephrite - The original jade treasured by the Chinese culture, nephrite is a calcium magnesium silicate and comes in a range of colors from white to green. The composition of nephrite is fibrous, making it one of the "toughest" materials on earth.
Olivine - A mineral family containing the gemstone peridot.
Opal - A unique gemstone with a beautiful play-of-color display which exhibits all colors and both light and dark base colors reflect a rainbow-like display of multiple colors when viewed from different angles. On Mohs' scale of hardness, opal is 5.5-6.5. Primary sources include Australia, Brazil, Guatemala, Honduras, Indonesia, Japan, Mexico, Russia, Nevada, and Idaho.
Organic Gemstones - Gemstones that are primarily non-mineral, being formed by plants and animals.
Orient - The layers of nacre that form a pearl contain tiny light-reflecting crystal. When there enough layers of crystals and they align in a certain way, the reflected light will form a prismatic effect on the surface of the pearl. The beautiful rainbow-like effect is known as "orient."
Padparadscha - Literally meaning "lotus flower," padparadscha refers to a lush pink and orange sapphire. Also, the most valuable topaz is pink to reddish orange and is called "padparadscha topaz."
Pearl - A lustrous, organic gem produced by saltwater oysters, freshwater mussels and occasionally by some shellfish. Exhibiting a range of colors from white to pink, silver, cream, peach, gold, green, blue and black they measure a 2.5-.5 on Mohs' scale of hardness. Primary sources of Sea Pearls include Persian Gulf; Gulf of Manaar; along the coasts of Madagascar, Burma, and the Philippines; many islands in the South Pacific, northern Australia; and the coastal lines of Central and northern South America; and some small beds in Japan. Primary sources of freshwater Pearls include the United States, some in Europe.
Peridot - A gemstone in the Olivine mineral family which exhibits a range of vibrant greens from yellow-green to olive green to brownish green. On the Mohs' scale of hardness, peridot is 6.5-7. Primary sources include Burma, Australia, Brazil, China, Kenya, Mexico, Pakistan, Sri Lanka, South Africa, Tanzania, and Arizona.
Petalite - A gemstone for collectors which is often colorless, but there are also examples of pink and yellow varieties. On the Mohs' scale of hardness, petalite is 6-6.5. It has a vitreous luster and sources include Western Australia, Brazil, Italy, Namibia, Sweden, Zimbabwe, and the United States.
Pigeon's Blood - While rubies come in a variety of red tones, the most valued color is pure red with a hint of blue, known as pigeon's blood red.
Precious Stones - See gem.
Pyrope - A variety of garnet that usually exhibits a blood-red color but can also be tinged with yellow or purple. On Mohs' scale of hardness, pyrope is 7-7.5. It has a vitreous luster and primary sources include Burma, China, Madagascar, Sri Lanka, South Africa, Tanzania, and the United States.
Quartz - One of the most common gem families and can be found all around the world. Quartz comprises several different groups of gems from crystalline quartz (crystals viewable by the naked eye) and crypto-crystalline (microscopic crystals). Crystalline quartz includes amethyst, aventurine, rock crystal, blue quartz, citrine, hawk’s eye, prasiolite, quartz cat's eye, smoky quartz, rose quartz, and tiger's eye. Crypto-crystalline quartz is also known as chalcedony and includes agate, bloodstone, carnelian, chrysoprase, jasper, moss agate, onyx, and sard.
Rhodolite - A variety of garnet that exhibits a lovely rhododendron red color with a lively luster. On Mohs' scale of hardness, rhodolite is 7-7.5. It has a vitreous luster and primary sources include Burma, China, Madagascar, Sri Lanka, South Africa, Tanzania, and the United States.
Rhodonite - This ornamental stone is translucent to opaque with a rose red color. It often resembles pink marble veined with black.
Rock Crystal - A colorless water-clear form of quartz, rock crystal was believed by some ancient Greeks to be ice that had hardened over time into stone.
Rubellite - A gemstone variety of the Tourmaline group. Valued for its ruby color, it exhibits a range of color from pink to red, sometimes with a violet tint. On Mohs' scale of hardness, rubellite is 7-7.5. It has a vitreous luster on crystal surfaces and a greasy luster on fractures. Sources include Brazil, Afghanistan, Australia, Burma, India, Madagascar, Malawi, Mozambique, Namibia, Nepal, Nigeria, Pakistan, Russia, Zambia, Zimbabwe, Sri Lanka, Tanzania, the United States, Zaire, Elba, and Switzerland.
Ruby - A gemstone in the Corundum family that exhibits a range of red colors, and the most desired color is pigeon’s blood (pure red with a hint of blue). On Mohs' scale of hardness, ruby is 9. It has a strong luster like diamonds and sources include Burma, Thailand, Sri Lanka, Tanzania, Afghanistan, Cambodia, Kenya, Madagascar, and Vietnam.
Rutilated Quartz - Quartz containing needle-like inclusions of rutile rods is known as rutilated quartz.
Sapphire - A gemstone in the Corundum family known for its beautiful "cornflower blue" color. On Mohs' scale of hardness, ruby is 9. It has a strong luster like diamonds and sources include Australia, Burma, Sri Lanka, Thailand, Montana, Brazil, Cambodia, China, Kenya, Madagascar, Malawi, Nigeria, Pakistan, Rwanda, Tanzania, Vietnam, and Zimbabwe.
Scapolite - A distinctly fibrous gemstone usually found in white, yellow, pink and violet hues. On Mohs' scale of hardness, scapolite is 5-5.6. It has a vitreous luster and sources include Burma, Brazil, Canada, Madagascar, and Tanzania.
Single Cut Diamond - This precursor to the modern brilliant cut emerged in the mid-1600s. Moving closer to a rounded shape, the cut consists of 8 facets surrounding the table and 8 facets below the girdle. It has a total of 18 facets. The single cut is often found on side stones or smaller stones.
Smoky Quartz - A variety of the Quartz family that exhibits brown to black and smoky gray colors. On Mohs' scale of hardness, smoky quartz is 7. Sources include Brazil, Madagascar, Russia, Scotland, Switzerland and the Ukraine.
Sodalite - A component of Lapis Lazuli, ornamental sodalite has a rich blue color and is sometimes mistaken for lapis.
Spessartite - A variety of garnet where the color ranges from a yellowish-orange to an intense aurora red to a deep-orangey color. On Mohs' scale of hardness, spessartite is 7-7.5. It has a vitreous luster and primary sources include Burma, China, Madagascar, Sri Lanka, South Africa, Tanzania, and the United States.
Sphene - A brilliant transparent gemstone which exhibits a range of colors from yellow to brown to green and even reddish. On Mohs' scale of hardness, sphene is 5-5.5. It has an adamantine luster and sources include Burma, Brazil, Mexico, Austria, Sri Lanka and the United States.
Spinel - The classification of a large group of related minerals that has a small group of gemstone quality stones. Spinel exhibits a wide range of colors including red, pink, orange, yellow, brown, blue, violet, purple, green and black. On Mohs' scale of hardness, spinel is 8. Sources include Burma, Cambodia, Sri Lanka, Afghanistan, Australia, Brazil, Madagascar, Nepal, Nigeria, Tadzhikistan, Tanzania, Thailand and the United States.
Star Sapphire - Sapphires that exhibit a natural asterism and must be cut cabochon in order to display this unique effect.
Sunstone - Known as aventurine feldspar, is a gemstone in the Feldspar group. It normally has a rich golden or reddish-brown color with sparkling red and brown (and sometimes green or blue) inclusions. On Mohs' scale of hardness, it is 6-6.5. Sources include India, Canada, Madagascar, Norway, Russia, and the United States.
Tahitian Pearls - Setting the standard for black pearls, Tahitian pearls are some of the most popular pearls in the world. They have a gentle, velvety luster and often exhibit a strong iridescence.
Tanzanite - A variety of zoisite that has naturally occurring shades of blue, green, yellow, pink, brown and khaki but virtually all gemstone quality crystals are heat treated to produce the highly valued shades of sapphire blue, amethyst, and blue violet. On Mohs' scale of hardness, tanzanite is 6.5-7. The prime source of the world's tanzanite is in Tanzania.
Tiger's Eye - Referring to a golden-brown quartz cabochon that reflects the floating play of light phenomena known as chatoyancy and asterism; thus, making the stone's appearance similar to a tiger's eye.
Topaz - A gemstone found in vivid colors such as yellow, orange, red-brown, light to dark blue, pink-red, red, violet, light green, colorless and in unusual colors such as mystic, ocean, glacier, patriot, canary, champagne, orchid, dawn, teal and kiwi. On Mohs' scale of hardness, it is 8. Topaz has a vitreous luster and sources include Brazil, Afghanistan, Australia, Burma, China, Japan, Madagascar, Mexico, Namibia, Nigeria, Pakistan, Russia, Zimbabwe, Sri Lanka and the United States.
Tourmaline - A fascinating mineral that can actually exhibit two or more colors in one crystal. It possesses one of the widest color ranges, reproducing every conceivable color in the universe. On Mohs' scale of hardness, tourmaline is 7.5. It is vitreous on crystal surfaces and greasy on fractures. Sources include Brazil, Afghanistan, Australia, Burma, India, Madagascar, Malawi, Mozambique, Namibia, Nepal, Nigeria, Pakistan, Russia, Zambia, Zimbabwe, Sri Lanka, Tanzania, the United States, Zaire, Elba, and Switzerland.
Tsavorite Garnet - A gemstone within the Garnet family that exhibits a green to emerald green color. On Mohs' scale of hardness, tsavorite is 7-7.5. It has a vitreous luster and sources include Kenya and Tanzania.
Turquoise - A translucent to opaque gemstone which exhibits a range of blue and green colors from sky-blue to blue-green to apple-green. On Mohs' scale of hardness, turquoise is 5-6 and is found in Iran, Afghanistan, Argentina, Australia, Brazil, China, Israel, Mexico, Tanzania, and the United States.
Zircon - A beautiful gemstone with a high refractive index and strong dispersion and exhibits a range of colors including yellow, brown, orange, red, violet, blue, green and colorless. On Mohs' scale of hardness, it is 6.5-7. It has a vitreous to brilliant luster and sources include Burma, Cambodia, Sri Lanka, Thailand, Australia, Brazil, Korea, Madagascar, Mozambique, Nigeria, Tanzania, and Vietnam.