Iron oxide black CAS #1309-38-2

MAGNETITE ,The mineral magnetite, ferroferric oxide, Fe3O4, is isometric, commonly occurring in octahedrons, dodecahedrons, and massive, granular, and laminated forms. It is brittle with an uneven fracture; cleavage is not distinct, but with pressure an octahedral parting may develop; hardness, 5.5–6.5; specific gravity, 5.18; luster, metallic to dull; color, iron black, streak, black. It is opaque and strongly magnetic; when possessing polarity it is known as lodestone.

Black iron oxide (Fe3O4) is a synthetic inorganic pigment, produced by oxidation of iron (II) hydroxide obtained from the action of alkali on iron (II) sulfate solution. The composition of the pigment corresponds with that of magnetite. The pigment is of fine texture, but has only low tinting strength in paint and other coatings. It is mainly used as a colorant in fillers, primers, and undercoats. The major black pigments in the paint industry are carbon blacks.