Gemstone Chart |
Natural Freshwater Pearl Freshwater pearls are a kind of pearl that comes from freshwater mussels.Freshwater pearls come in many shapes from round to button shapes, from flat flakes to rice shapes and in many colors. As with the salt water Akoya pearl the round shapes are generally more expensive. Color: orange, pink, white, gray, light purple, rose, black, brown, gold, yellow, silvery, green, blue, bronze. Categories: semi-precious stone Chemical Composition: CaCO3 Crystal Group: Not applicable Hardness: 3.5 - 4.0 Density: 2.66 ¨C 2.78+ Occurrence: China, Japan
| 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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