Gemstone Chart |
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.
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