Iron Oxides

compounds of divalent and trivalent iron with oxygen: ferrous oxide, FeO; ferric oxide, Fe₂O₃; and fertosoferric oxide, Fe₃O₄. Natural iron oxides (the minerals hematite, Fe₂O₃, and magnetite, Fe₃O₄) are raw materials in producing iron. Iron oxides are used as pigments; ferromagnetic iron oxides (Fe₃O₄ and γ-Fe₂O₃) are used in making magnetic materials.