Gem-quality specimens of the mineral olivine are called peridot by gemmologists. Peridot has an olive- or bottle-green colour due to the presence of iron, and a distinctive oily or greasy lustre. It has a high birefringence, so doubling of the back facets can easily be seen in larger specimens when viewed from the front. Good- quality crystals are very rare.
Peridot is found on St. John’s Island(Egypt), in China, Burma, Brazil, Hawaii and Arizona(USA), Australia, South Africa, and Norway.
|Luster||Vitreous to greasy|
|Refractive Index||1.64 to 1.69|