Reduction of magnetite ore by CO in a blast furnace is used to produce<unk>  as part of steel production process: :{Fe3O4} + 4CO -> {3Fe} + 4CO2 Controlled oxidation of<unk> 3O4 is used to produce brown pigment quality γ-Fe2O3 (maghemite): : More vigorous calcining (roasting in air) gives red pigment quality α-Fe2O3 (hematite): :
Iron
Zinc
Copper 
Biotin
Folate
Selenous acid
Calamine
Sybil 