Iron oxide black       

     Iron oxide is a kind of Black powder, the particle is in spherical structure, and molecular formula is Fe₃O₄(FeO·Fe₂O₃).
 

     Iron oxide black has a saturated blue ink shade, relative density is 4.73 g/cm3, and covering power and tinting strength are very high.

    Iron oxide black is very stable in the effect of light and atmosphere, not soluble in alkali, slightly soluble in dilute acid, completely dissolved in concentrated acid.

    The heat resistance of iron oxide black is poor, at higher temperatures, it is easy to be oxidized and become red iron oxide. Under normal circumstances, after 200 degrees calcination  iron oxide black can be converted to γ-Fe2O3, and in 300 degrees or more converted into α-Fe2O3, which also has a strong magnetic, can be attracted by the magnet.