Salt Saliva Metal

Iron oxides are chemical compounds composed of iron and oxygen. All are black magnetic solids. Oxyhydroxides are a related class of compounds, perhaps the best known of which is rust.[1]

Iron oxides and oxyhydroxides are widespread in nature and play an important role in many geological and biological processes. They are used as iron ores, pigments and catalysts. They also occur in hemoglobin. Iron oxides are durable pigments in paints and cosmetics.