Chromium(III) oxide (Cr?O?) is an amphoteric compound found in the rare mineral eskolaite. It is widely used in industrial products such as abrasives, refractories, semiconductors, pigments, alloys, textiles, printing, inks, catalysts, coloured glass, welded metals, and dyed polymers.

Cr?O? is an antiferromagnetic crystal with a Neel temperature of 307 K. It crystallises in a corundum-type centrosymmetric trigonal structure in the R?3c space group.Cr3? combines with six equivalent O2 atoms to form a mixture of corner-, face-, and edge-sharing CrO? octahedra.The corner-sharing octahedra have tilt angles between 47-60°. The tilt angles of the corner-sharing octahedra range from 47-60°. the Cr-O bond lengths are three shorter (1.97 ?) and three longer (2.02 ?). o2- bonds with four equivalent Cr3? atoms to form a mixture of twisted corner-conjugated and edge-conjugated OCr? trigonal pyramids. the O2- bonds with six equivalent O2 atoms to form a mixture of corner-conjugated and edge-conjugated CrO? octahedra.