Minerals > Chromite

Chromite is the most important ore of chromium from which it derives its name. Chromium is an important metal with a wide range of industrial uses that includes the production of Ferro-chromium for metallurgical applications, refractories and foundry sands. It is a brownish black to a deep dark black in colour and registers 5.5 on the Mohs hardness scale.

Chromite forms in deep ultra-mafic magmas and is one of the first minerals to crystallize. It is because of this fact that chromite is found in some concentrated ore bodies. While the magma is slowly cooling inside the Earth's crust, chromite crystals are forming and, because of their density, fall to the bottom and are concentrated there.

Although its primary origin is ultra-mafic rocks such as peridotites, chromite is also found in metamorphic rocks such as serpentites. Chromite, as is indicated by its early crystallization, is resistant to the altering affects of high temperatures and pressures. Thus, it is capable of going through the metamorphic processes unscathed, while other minerals around it are being altered to perpentine, biotite and garnets.

Chromite is a key ingredient in high value stainless steel because of corrosion resistant properties, which gives the alloy its unique characteristics. About 85% of chromite ore produced worldwide is used in the stainless and other specialty steel applications, after conversion to a Ferro-chrome alloy; Chromium chemicals account for 8%; foundry applications for 5%; and, refractories for 2%.

World production of chromite was estimated at 14.0 million tones in 2003, with major producers being South Africa, Kazakhstan, India, Iran and Pakistan.