Gemstone Chart |
Natural Andradite Andradite is a Garnet, belonging to the Garnet group. It has the most powerful luster of any garnet, and this makes it a reputable gem. Color: brown, greenish brown, yellowish green, green Categories: semi-precious stone Chemical Composition: Ca3Fe2(SiO4)3 Crystal Group: Cubic Refractive Index: 3.82 ¨C 3.85 Hardness: 6.5 Density: 1.888 ¨C 1.889 Occurrence: Mexico, Korea, Namibia, Russia, Iran, South Africa
| Natural Apatite Apatite displays strong fluorescence under short wave ultra-violet light. There is a particularly intense and deeply saturated, geenish-blue (aka swiss blue) variety from Madagascar known as "Neon Apatite" that is becoming quite popular in the gem trade. Color: yellow, green, below, violet Categories: semi-precious stone Chemical Composition: Phosphate group Crystal Group: Hexagonal Refractive Index: 1.63-1.64 Hardness: 5 Density: 3.17-3.23 Occurrence: Burma, Ceylon, Madagascar, Mexico, Canada, India
| 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 Citrine Citrine is any quartz crystal or cluster that is yellow or orange in color. Although often cut as a gemstone, citrine is actually somewhat rare in nature. Color: Yellow, orange Categories: semi-precious stone Chemical Composition: SiO2 Crystal Group: Trigonal Refractive Index: 1.544-1.553 Hardness: 7 Occurrence: Brazil, Uruguay, Mexico, Russia, USA.
| Natural Danburite Danburite is a very spiritual stone that carries a pure vibration. With a hardness of 7, danburite is quite hard and suitable for any kind of jewelry. Danburite handles easily and ordinarily offers no problems for lapidaries. It makes an especially brilliant gem because of its extreme clarity. Color: White, yellowish, very light pink, buff colored, very light brown Categories: semi-precious stone Chemical Composition: calcium borosilicate Crystal Group: Orthorhombic Refractive Index: 1.630(+.003,-.003) - 1.636 (+.003, -.003) Hardness: 7 Density: 3 Occurrence: Danbury, Connecticut and Russell, New York, USA; Charcas, San Luis Potosi, Mexico; Kyushu Island, Japan; Mogok, Burma and Uri, Switzerland; Madagascar.
| Natural Hessonite Hessonite is one of the gem varieties of the garnet mineral, grossular. Hessonite is usually cinnamon brown and has been called "cinnamon stone". Hessonite can also be orange; this color is becoming common on the gem markets. Color: Brownish-orange, brownish yellow, aurora red Categories: semi-precious stone Chemical Composition: Ca3Al2(SIO4)3 Crystal Group: Cubic Refractive Index: 1.72-1.74 Hardness: 7.25 Density: 3.65 Occurrence: Sri Lanka, Mexico, Brazil, Canada, Madagascar
| 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 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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