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 Mali Garnet Mali Garnet is a mixture of grossular (calcium aluminum silicate) and andradite (calcium iron silicate ). It is a yellow-green variety of grossular with a slight overlap in the grossular-andradite series.Mali garnet is one of the latest discoveries in the garnet family. Color: yellow, brown, green. Categories: semi-precious stone Chemical Composition: Ca3Al2(SiO4)3 Crystal Group: Cubic Refractive Index: 1.72-1.748 Hardness: 7.25 Density: 3.65 Occurrence: Mali
| Natural Mawsitsit Mawsitsit is a rare, intense green variety of jadeite found in Burma.Mawsitsit is named for its source location, the small village of Mawsitsit.It is found in only one deposit on earth.. Color: Green with black spots Categories: semi-precious stone Crystal Group: Not applicable Refractive Index: 1.52 Hardness: varies, up to 7 Density: 2.5-3.2 Occurrence: Mawsitsit, Burma
| Natural Musgravite Musgravite is an extremely rare member of the taaffeite family that was discovered in 1967 in the Musgrave Range of South Australia. It is also one of rare gemstones that have been sought these years for the collection at GAAJ laboratory. Color: pale olive green, grey, mauve, grey purple Categories: semi-precious stone Chemical Composition: (Fe2+,Zn,Mg)2Al6BeO12 Crystal Group: Hexagonal Refractive Index: 1.717 - 1.739 Density: 3.68 Occurrence: The Musgrave Mountain Ranges in Central Australia
| 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 Opal Opal is the most colorful of all gems. It is a form of silica chemically similar to quartz, but more like glass and containing a variable amount of water within the mineral structure. Its splendid play of color is unsurpassed, and fine examples can be more valuable than diamond. Precious opals (black and white) are cut and polished into cabochons and used in all forms of jewelry. Color: White, green, blue, black, red, orange, violet, pink, grey, yellow. Categories: precious stone Chemical Composition: SIO2nH2O Crystal Group: Amorphous Refractive Index: 1.44-1.46 Hardness: 5.5 - 6.0 Density: 2.65 - 3.00 Occurrence: Czechoslovakia, Mexico, Honduras, Australia, Brazil, Tanzania.
| Natural Peridot Peridot is the best known gem variety of olivine, a species name for a series of magnesium-iron rich silicate minerals.It is one of the prettiest of all green gems.Most peridot formed deep inside the earth and was brought to the surface by volcanoes. Some has also come to Earth in meteorites, but this extraterrestrial peridot is extremely rare, and you're not likely to see it in a retail jewelry store. Color: Green, olive. Categories: semi-precious stone Chemical Composition: (Mg,Fe)2(SiO)4 Crystal Group: Orthorhombic Refractive Index: 1.654-1.689 Hardness: 6.5 Density: 3.34 Occurrence: China, Burma, East Africa, U.S.A., and Vietnam
| Natural Prehnite Prehnite is a hydrated calcium aluminum silicate that occurs in a soft yellow-green to apple-green color.It was a rare gemstone, most prehnite is translucent but transparent specimens are sometimes found.While you are unlikely to find it in your local jewelry store, gemstone dealers often have some supply. Deposits are found in South Africa, Australia, China, Scotland and the United States. Color: yellow green, brown, yellow brown, oil green Categories: semi-precious stone Chemical Composition: (CA2Al2SI3O10(OH)2) Crystal Group: Orthorhombic Refractive Index: 1.61 - 1.64 Hardness: 6 Density: 2.80 - 2.95 Occurrence: China, France, U.S.A., Scotland, Australia
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