What is a chromitite in geology ?

Chromitite : definition

A chromitite is a rock composed mainly of grains of chromite (sometimes more than 95%) embedded in interstitial silicates, mainly bronzite, olivine (forsterite) and anorthite. When olivine becomes the main constituent with chromite, it is called chromite dunite. Chromitites are sometimes related to magnesian gabbros and norites.

Chromitites appear in magmatic segregations within basic stratified complexes (the Bushveld in South Africa, for example) and constitute very important chromium deposits.