chroomThe main source of chromium is the black mineral iron chromite (FeCr2O4) which is mainly mined in South Africa, Kazakhstan, India and Turkey. Also in calcium chromate CaCrO4 and lead chromate PbCrO4 is sufficient chromium.
Chroma is Greek for color. Chrome is yellow pigment for paint and glass.
Chromium (III) is an essential nutrient of which is not much known.
One can isolate metallic chromium from chromium oxide by heating it in a wood oven. Chromium -bearing ore can be converted to chromium (VI) oxide, CrO3. This chromium oxide can be reduced to chromium or aluminum by means of electrolysis. One can also heat the mineral iron chromite (FeCr2O4) in the presence of aluminum or silicon. If not the pure chromium is required, one can also make ferro-chromium by reduction with carbon. A mixture of iron oxide and chromium oxide, Chromium (VI) is irritating and dangerous. It occurs in cement and tanned leather.
The melting point is 1,875°C and the boiling point 2,672°C.
Chromium makes steel stainless and hard.

Chromium also is in the atmosphere as small particles.