Iron oxides are chemical compounds. There are sixteen known iron oxides. Iron oxides are used in pigments. It is used in both man-made and natural pigments.
Venetian red (haematite), Magnetite (Fe304), or a mixture of oxides make black or purple pigments. The umber’s, sienna’s and ochre’s are oxides or hydrated oxides of a yellow to chestnut colour.
Various iron oxides
- Iron(III) oxide, reddish, commonly known as rust, found in the earth as haematite
- Iron(II,III) oxide, magnetic, black, found in the earth as magnetite
- Iron(II) oxide, black, rare, flammable, not stable at room temperature
- Iron(II) hydroxide, dark green hydrated iron oxidede:Eisen#Oxide