Gemstone Chart |
Natural Agate Agate is a beautiful natural chalcedony stone, classified as a semi precious gem and has been used by people as early as the ancient Egyptians in and before 3000 BC! Agate is hard and tough enough to be incorporated into jewelry and other ornamental items. Color: Blue, green, yellow,orange, brown, gray Categories: semi-precious stone Chemical Composition: SiO2 Crystal Group: Hexagonal Refractive Index: 1.530 - 1.539 Hardness: 6.5 - 7 Density: 2.57 - 2.64 Occurrence: Scotland, U.S.A., India, England, Italy, Brazil, Uruguay, Germany, Egypt, Indonesia, and many other localities.
| Natural Chalcedony Chalcedony is a catch all term that includes many well known varieties of cryptocrystalline quartz gemstones. They are found in all 50 States, in many colors and color combinations, and in sedimentary, igneous, and metamorphic rocks. Color: grayish, purple, white, green, blue, lavender, yellow, brown Categories: semi-precious stone Chemical Composition: SiO2 Crystal Group: Hexagonal Refractive Index: 1.530 - 1.539 Hardness: 6.5 Density: 2.57 ¨C 2.64 Occurrence: Brazil, U.S.A. Germany, India, Uruguay, Austarlia, Egypt, Italy, Scotland, South Africa, Namibia, Madagascar, Mexico, Tanzania, and many other localities throughout the world.
| Natural Fluorite Fluorite has a wide range of colors including yellow, blue, pink purple and green. It is an interesting and beautiful gemstone. Color: Colorless, yellow, brown, green, blue, violet, pink Categories: semi-precious stone Chemical Composition: CaF2 Crystal Group: Cubic Refractive Index: 1.43 Hardness: 4 Density: 3.18 Occurrence: Namibia, U.K., Switzerland, Nigeria, Czechoslovakia, Canada, Poland, Italy, Norway, Germany, U.S.A.
| 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
| Natural Sapphirine Sapphirine is a rare mineral, a silicate of magnesium and aluminium.Though Sapphirine clearly falls into the "rare stone" category, it is a relatively durable stone with a Moh's hardness of 7.5. Sapphirine's very distinctive appearance along with their somewhat unusual durability have made them fairly popular with collectors. Color: Pale blue, bluish gray, greenish gray, green, purplish pink Categories: semi-precious stone Crystal Group: Monoclinic Refractive Index: 1.714-1.723 Hardness: 7.5 Density: 3.4-3.5 Occurrence: U.S.A., U.K., Sweden, Czechoslovakia, Japan, South Africa, Greenland, Madagascar, Italy, Sri Lanka
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