Gemstone Chart |
Natural Demantoid The demantoid is one of the most brilliant gemstones that exist, yet until recently it was little known except among collectors and gemstone lovers. Color: Green, yellow green. Categories: semi-precious stone Chemical Composition: Ca3Fe2(SiO4)3 Crystal Group: Cubic Refractive Index: 1.888 - 1.889 Hardness: 6.5 Density: 3.82 - 3.50 Occurrence: Russia, Namibia, Iran, South Africa
| Natural Dioptase Dioptase is an intense emerald-green to bluish-green copper cyclosilicate mineral.Dioptase is a rather unusual gemstone that will rarely be found in your basic jewelry stores. It is a beautiful gemstone with a very unusual combination of green colors. Color: Dark blue green, emerald green, or turquoise Categories: semi-precious stone Chemical Composition: CuSiO2(OH) 2 Crystal Group: Hexagonal Refractive Index: RI 1.644 ¨C 1.709 Hardness: 5 Density: 3.28 ¨C 3.55 Occurrence: Russia, Tsumeb Namibia, California and Colorado USA, Congo, Zaire, Chile
| Natural Euclase Euclase is a rare mineral, resembling beryl in color and hardness.Euclase is found in granitic pegmatites with other gem minerals such as topaz and beryl. Color: White, pale blue, greenish blue, dark blue. Categories: semi-precious stone Chemical Composition: BeAlSiO4(OH) Crystal Group: Monoclinic Refractive Index: 1.652-1.672 Hardness: 7.5 Density: 3.18 Occurrence: Brazil, Tanzania, Russia, Zimbabwe, Madagascar, Austria.
| Natural Hemimorphite Hemimorphite is a usually white or colorless mineral, essentially Zn4Si2O7(OH)2¡¤H2O, an important ore of zinc. Also called calamine. Color: Light blue, dark blue, green ,white. Categories: semi-precious stone Chemical Composition: (Zn4Si2O7(OH)2.H2O) Crystal Group: Orthorhombic Refractive Index: 1.612-1.633 Hardness: 5 Density: 3.44 Occurrence: Franklin and Sterling Hill New Jersey, New Mexico, Montana, Arizona, U.S.A; Congo; Nerchinak in Transbaikalia, Siberia; Zambia; Santa Eulalia and Mapimi, Mexico; England; Wenshan, Yunnan Province, China.
| Natural Idocrase Primarily a green color that will resemble jade.idocrase is one stone that is sometimes mistaken for jade by jewelers and consumers alike. Idocrase is from the greek and means mixed form, an allusion to its crystals showing a mixture of other mineral forms. Color: normally green, but also can be brown, yellow, blue and/or purple. Categories: semi-precious stone Chemical Composition: nesosilicate or sorosilicate Crystal Group: Tetragonal Refractive Index: 1.71 - 1.73 Hardness: 6.5 Density: 3.3 - 3.5 Occurrence: Quebec, Canada; California and the New England region of USA; Mt Vesuvius, Italy; Ural Mountains, Russia, Switzerland, East Africa
| Natural Jadeite A rare, usually green mineral of the pyroxene group. Jadeite can also occur in white, auburn, buff, or violet varieties. The most highly valued form of jade consists of jadeite.Jade has a history in China of at least four thousands years.Experts believe that, although more expensive, diamonds and gold cannot be compared with jade - jade is animated with a soul. Color: Pure white thru pink, brown, red, orange, yellow, mauve, violet, blue, and black, to an extensive range of green and mottled green and white. Categories: semi-precious stone Chemical Composition: NaAl(SiO3)2 Crystal Group: Monoclinic Refractive Index: 1.654 - 1.667 Hardness: 7 Density: 3.32 Occurrence: Northern Myanmar. Non commercial discoveries of Jadeite have also been reported in China; Russia (in the Polar Urals); Niigata, Japan; San Benito County, California, USA, and Guatemala.
| 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.
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