Olivine-a common mineral found on the Earth’s subsurface-is a magnesium iron silicate. The ratio of magnesium and iron varies between the two end members, forsterite (magnesium end member) and falalite (iron end member).

Forsterite has an unusually high melting point at 1900 °C, while fayalite melts at 1200 °C. The melting points as well as the other properties vary smoothly between the two end members. Olivine group is a group of minerals which have a related structure.

Olivine is named for its typically olive-green color. But it may change to a reddish color due to the oxidation of iron. Peridot is the translucent variety of olivine used as a gemstone. It is also called chrysolite or chrysolithe.

Some of the finest gem-quality olivine has been obtained from a body of mantle rocks on Zabargad island in the Red sea.