A

David

Darling

olivine

olivine

Olivine is any of a group of silicate minerals which are orthosilicates of magnesium and iron (Mg, Fe)2SiO4. Olivine forms olive-green crystals in the orthorhombic system, and occurs commonly in igneous rock, chiefly basalt, gabbro, and peridotite. The transparent variety peridot is used as a gemstone. Olivine is also found in some meteorites, such as carbonaceous chondrites.