Gemstone Chart |
Natural Lapis Lazurite is a popular but generally expensive mineral. Well-formed, deep blue crystals are rare and valuable. Lapis lazuli is a gemstone of the kind that might have come straight out of the Arabian Nights: a deep blue with golden inclusions of pyrites which shimmer like little stars. Color: Blue, greenish-blue, violet blue Categories: semi-precious stone Chemical Composition: A complex aggregate Crystal Group: Not applicable Refractive Index: 1.5 Hardness: 5.5 Density: 2.7-2.9 Occurrence: Afganistan, Pakistan, Chile, Russia, U.S.A., Angola, Burma
| Natural Oligoclase Oligoclase is a rock-forming mineral belonging to the plagioclase feldspars. Oligoclase is famous for its two gem varieties: Sunstone and Moonstone. Color: green, orange, red, colorless Categories: semi-precious stone Chemical Composition: [Na,Ca]AlSi3O8 Crystal Group: Triclinic Refractive Index: 1.53 - 1.54 Hardness: 6 - 6.5 Density: 2.62 - 2.65 Occurrence: Tvedestrand and Hitero on the south coast of Norway; near Lake Baikal Russia; Ontario, Canada; Tanzania; Kangayam, southern India; France; and in Maine, New Mexico, New York, North Carolina, Pennsylvania, Virginia and Oregon in the USA.
| Natural Phenakite phenakite is a fairly rare nesosilicate mineral consisting of beryllium orthosilicate, It is one of the brightest of the colorless gemstones.Madagascar seems to be the most important source for this rare stone. Color: White Categories: semi-precious stone Chemical Composition: Be2SiO4 Crystal Group: Hexagonal Refractive Index: 1.651-1.696 Hardness: 7.5-8.0 Density: 2.94--2.96 Occurrence: Russia, Madagascar, U.S.A., Brazil, France, Switzerland, Ceylon, E. Africa.
| 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 Turquoise Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium.The gem turquoise owes it's beauty almost entirely to its superb color. It has been used for ornamentation since 3000BC and possibly before. Color: Blue, Greenish Blue Categories: semi-precious stone Chemical Composition: CuAl6(PO4)4(OH)85H2O Crystal Group: Triclinic Refractive Index: 1.62 Hardness: 5.5-6 Density: 2.60- 2.90 Occurrence: Iran, USA, India, Tibet, China, Egypt, Chile, Russia, Australia
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