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.

Crystal Structure Orthorhombic
Composition Magnesium Silicate
Colour Yellowish green
Luster Vitreous to greasy
Refractive Index 1.64 to 1.69
Specific Gravity 3.34
Mohs Hardness 6.5
DR 0.036