As a fine powder it is used for polishing. It is also used as pigment and finds its way into cosmetics. It is magnetic and has been used on magnetic tapes and hard disks.
Ferric oxide is any one of a range of chemical compounds made up of iron and oxygen. Most of these are naturally occurring; some form in the soil or in chemical deposits in rocks or mountains, and rust is also a very common and well-known source. Not all oxides are useful to humans, but several varieties play key roles in industry, cosmetics, and art. Manufacturers often rely on them to add pigment as well as to provide certain electronic and magnetic properties to things like bankcards and digital scanning devices.