Iron(II) oxide III and forms insoluble hydroxides in water. Iron(II) oxide is used as a pigment. It is FDA-approved for use in cosmetics and it is used in some tattoo inks. It can also be used as a phosphate remover from home aquaria. Iron(II) oxide Iron(II) oxide or ferrous oxide is the inorganic compound with the formula FeO. Its mineral form is known as wüstite. One of several iron oxides, it is a black-colored powder that is sometimes confused with rust, the latter of which consists of hydrated iron(III) oxide (ferric oxide). Iron(II) oxide also refers to a family of related non-stoichiometric
Chromium(IV) oxide of both the chromium dioxide pigment and chrome tapes, basing its VHS & S-VHS video tape, audio cassettes, and 3480 data cartridges on this formulation. Dupont and BASF had also introduced chrome-cobalt "blended" oxide pigments which combined about 70% cobalt-modified iron oxide with 30% chrome oxide into a single coating, presumably to offer improved performance at lower costs than pure chrome. Many high grade VHS tapes also used much smaller amounts of chrome in their formulations because its magnetic properties combined with its cleaning effects on heads made it a better choice than aluminium oxide or other non-magnetic materials added