Gemstone Chart |
Natural Beryl Beryl is a semi-precious clear gemstone which usually comes in greens, yellows, and occasionally pinks, ands various shades thereof. Color: Green, blue, pink, yellow, red Categories: semi-precious stone Chemical Composition: Be3Al2(SiO3)6 Crystal Group: Hexagonal Refractive Index: 1.577(+-.016), 1.583 (+-.017) Hardness: 7.5 Density: 2.67-2.745 Occurrence: Austria, Columbia, Brazil, Russia, East Africa, Australia, Madagascar, South Africa, Zimbabwe, India, Pakistan, Zambia, Nigeria, U.S.A., Afghanistan
| 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 Chrysoprase Chrysoprase is a gemstone variety of chalcedony or cryptocrystalline quartz, colored by trace amounts of nickel. Categories: semi-precious stone Chemical Composition: SIO2 Crystal Group: Hexagonal Refractive Index: 1.544 - 1.553 Hardness: 7 Density: 2.65 - 2.66 Occurrence: Australia, Tanzania
| Natural Diamond Diamond is the ultimate gemstone, having few weaknesses and many strengths. It is well known that Diamond is the hardest substance found in nature. Color: White, yellow, brown, black. Rarely, blue, red, or pink. Categories: precious stone Chemical Composition: C Crystal Group: Cubic Refractive Index: 2.417 Hardness: 10 Density: 3.52 Occurrence: Africa, Russia, Canada, Australia, India
| 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 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 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 Scheelite Scheelite is a calcium tungstate mineral with the chemical formula CaWO4.With a hardness of 4.5 to 5 on the Moh's ScaleScheelite is a rather soft stone. Traditionally, it was considered a collector's gem and unsuitable for use in jewelry. Color: Yellowish-white, brownish, orange yellow Categories: semi-precious stone Chemical Composition: CaWO4 Crystal Group: Tetragonal Refractive Index: 1.918 - 1.937 Hardness: 4.5 - 5.0 Density: 5.9 - 6.1 Occurrence: Czechoslovakia; Italy; Switzerland; Finland; Cumberland, Cornwall, England; Santa Cruz, Sonora, Mexico; South Dakota, Conneticut, Colorado, Utah, California, Arizona, USA; New South Wales and Queensland, Australia; Mian Yang, and Ping Wu, Sezhuan, China; Hollinger Mine, Ontario, Canada;
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