Gemstone Chart |
Natural Scheelite Scheelite is a calcium tungstate mineral with the chemical formula CaWO4.With a hardness of 4.5 to 5 on the Moh's ScaleScheelite is a rather soft stone. Traditionally, it was considered a collector's gem and unsuitable for use in jewelry. Color: Yellowish-white, brownish, orange yellow Categories: semi-precious stone Chemical Composition: CaWO4 Crystal Group: Tetragonal Refractive Index: 1.918 - 1.937 Hardness: 4.5 - 5.0 Density: 5.9 - 6.1 Occurrence: Czechoslovakia; Italy; Switzerland; Finland; Cumberland, Cornwall, England; Santa Cruz, Sonora, Mexico; South Dakota, Conneticut, Colorado, Utah, California, Arizona, USA; New South Wales and Queensland, Australia; Mian Yang, and Ping Wu, Sezhuan, China; Hollinger Mine, Ontario, Canada;
| Natural Spessartite The Spessartite is one of the most popular of all garnets. It is highly desired by collectors, jewelry designers and gem lovers.The sources for gem quality spessartine are Sri Lanka and Brazil. Color: Orange, yellow, brown Categories: semi-precious stone Chemical Composition: Mn3Al2(SiO4)3 Crystal Group: Cubic Refractive Index: 1.79-1.81 Hardness: 7.25 Density: 4.14-4.20 Occurrence: Germany, Ceylon, Burma, Nigeria, Maevatanana-Madagascar, Isoanala-Madagascar, East Africa.
| Natural Sphalerite Sphalerite is one of the very few minerals that has a total of six directions of cleavage, and occurs in many different colors. It is an unusual rare gemstone which is craved for by people as it possesses more brilliance than diamonds. Color: Orange, yellow, brown, green Categories: semi-precious stone Chemical Composition: ZnS Crystal Group: Cubic Refractive Index: 2.37 Hardness: 3.5-4 Density: 4.05 Occurrence: Spain, Mexico
| Natural Spinel Spinel is the magnesium aluminium member of the larger spinel group of minerals. It has the formula MgAl2O4.Pure spinel is white, but impurities give it a wide range of colors.Almost all colors are used in jewelry, but the most valuable and popular color is the deep red. Spinel is cut into gems for use as jewelry. The deep-red variety, known as ruby spinel, is the most prized form. Color: orange, pink, black, blue, lavender, mauve, greenish blue, and vivid red Categories: semi-precious stone Chemical Composition: MgAl2O4 Crystal Group: Cubic Refractive Index: 1.718 (-.006,+.044) Hardness: 8 Density: 3.60 (-.03, +.30) Occurrence: Mogok, Burma; Sri Lanka; Amboseli district, Kenya; Jemaa district, Nigeria; Matombo, Umba, and Tunduru Tanzania; Hunza, Pakistan; Pamir range, Tajikstan; Luc Yen, Vietnam; Madagascar; Australia; Sweden; Brazil.
| Natural Sunstone Sunstone is a sodium-calcium-aluminum-silicate variety of plagioclase feldspar, which when viewed from certain directions exhibits a brilliant spangled appearance; this has led to its use as a gemstone. Color: Orange-red, brownish-red Categories: semi-precious stone Chemical Composition: NaAlSi3O8 Crystal Group: Triclinic Refractive Index: RI 1.54 ¨C1.55 Hardness: 6 Density: SG 2.62 ¨C 2.65 Occurrence: Near Lake Baikal Russia; East Africa; Hastings, Renfrew, and Haliburton, in Ontario Canada; Tvedestrand, Hitero, Norway; Kangayam, India; Maine, Oregon, New Mexico, California, and North Carolina, USA.
| Natural Topaz Topaz is a silicate mineral most often found in igneous rocks of felsic composition. It is a common gemstone that has been used for centuries in jewelry. Gem quality topaz most commonly occurs in nature as a colorless crystal. It is a very popular gemstone. Color: colorless, blue, yellow-brown, pinkish orange, red-orange, red-brown, tan. Categories: semi-precious stone Chemical Composition: AL(F,OH)2SIO4 Crystal Group: Orthorhombic Refractive Index: 1.629 - 1.637 Hardness: 8 Density: 3.52 - 3.56 Occurrence: Brazil, Sri Lanka, Nigeria, Germany, Australia, Japan, Russia, Ireland, Zimbabwe.
| Natural Tourmaline Tourmaline is actually a group of several different minerals which have similar crystal structures, but complex and variable chemical formulas. Tourmaline is the most varicolored of all gemstones. It occurs in all colors, but red, green, and multicolored are its most famous gem colors. Color: blue, bluish green, green, greenish blue, green-blue or blue-green, greenish yellow, orangy red, red, red-orange or orange-red, red-purple or purple-red, slightly purplish red, slightly yellowish green, strongly purplish red, strongly yellowish green, very slightly bluish green, yellowish green, yellow-green or green-yellow, colorless, brown, pink Categories: semi-precious stone Chemical Composition: (NaCa)(LI,MgFe,Al)9B3Si6(O,OH)31 Crystal Group: Hexagonal Refractive Index: 1.624(+.005, -.005) - 1.644(+.006, -.006) Hardness: 7-7.5 Density: 3.06 (.05, +.15) Occurrence: Brazil, East Africa, Nigeria, Madagascar, U.S.A.
| Natural Zircon Zircon is a mineral belonging to the group of nesosilicates. It is one of the heaviest gemstones, which means that it will look smaller than other varieties of the same weight. Zircon occurs in a wide range of colours,the most popular colour is blue zircon. The wide variety of colours of zircon, its rarity, and its relatively low cost make it a popular collector's stone. Color: Brown, blue, red, orange, white, green Categories: semi-precious stone Chemical Composition: ZrSiO4 Crystal Group: Tetragonal Refractive Index: 1.780-1.984 Hardness: 7.5 Density: 4.00-4.73 Occurrence: Ceylon, Burma,France, Norway, East Africa,Australia, SE Asia.
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