Gemstone Chart |
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 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.
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