Calcium Chromite, CaO.Cr₂O₃

Calcium Chromite, CaO.Cr₂O₃, is an olive-green crystalline powder of density 4.8 at 18° C. and hardness 6. It is produced by heating together calcium chloride and potassium dichromate, and subsequent extraction with concentrated hydrochloric acid. A compound, 2CaO.Cr₂O₃, is obtained by the interaction of ammonia and aqueous chrome alum and calcium chloride, while by direct combination of the oxides in the electric furnace, transparent green crystals of composition 4CaO.Cr₂O₃ are formed.