Iron Oxide (ferric oxide)

Molecular formula: Fe2O3

Iron(III) oxide or ferric oxide (Fe2O3): known in its natural state as rouge or hematite (also haematite), but also purified for use as a coating in magnetic audio and computer media, where it is known as ferric oxide. In a dry or alkaline environment it can cause passivation and inhibits rust. It is also a component of rust.