Chromium sulphide

Chromium sulfide, primarily chromium(III) sulfide with the formula Cr₂S₃, is an inorganic compound appearing as a brown-black hexagonal crystalline solid. It has a molecular weight of 200.19 g/mol and a density of about 3.77 g/cm³. The structure combines features of nickel arsenide (1:1 stoichiometry) and Cd(OH)₂ (1:2 stoichiometry), with short Cr-Cr distances indicating metal-metal bonding, and exists in nonstoichiometric forms ranging from CrS to Cr₀.₆₇S.​

It is insoluble in water, decomposing in it, and has a melting point around 1350°C. Chromium sulfide exhibits typical transition metal sulfide properties, including low solubility and stability, though it may react under specific conditions. Other forms like CrS (chromium(II) sulfide) exist but are less common.​

Used in ceramics, pigments, and as a semiconductor material, it requires careful handling due to potential toxicity from chromium compounds.​