|Systematic name: iron (III) oxide a red crystalline insoluble oxide of iron that occurs as haematite and rust and is made by heating ferrous sulphate: used as a pigment and metal polish (jeweller's rouge), and as a sensitive coating on magnetic tape. Formula: Fe2O3|
A reddish-brown to silver or black compound which occurs naturally as the mineral hematite and as rust. It is often used as a pigment and a metal polish. Chemical formula: Fe2O3.