Iron Cobalt Chromite Black Spinel, an inorganic pigment, is a reaction product of high temperature calcination in which Iron (II) Oxide, Cobalt (II) Oxide, Iron (III) Oxide, and Chromium (III) Oxide in varying amounts are homogeneously and ionically interdiffused to form a crystalline matrix of spinel. Its composition may include any one or a combination of the modifiers Al2O3, B2O3, CuO, MnO, NiO, or SiO2