information:classification
Oxides and sulfides

Iron forms various oxide and hydroxide compounds; the most common are iron(II,III) oxide (Fe O), and iron(III) oxide (Fe O). Iron(II) oxide also exists, though it is unstable at room temperature. Despite their names, they are actually all non-stoichiometric compounds whose compositions may vary. These oxides are the principal ores for the production of iron (see bloomery and blast furnace). They are also used in the production of ferrites, useful magnetic storage media in computers, and pigments. The best known sulfide is iron pyrite (FeS), also known as fool's gold owing to its golden luster. It is not an iron(IV) compound, but is actually an iron(II) polysulfide containing Fe and S ions in a distorted sodium chloride structure.