Iron oxide is a chemical compound composed of iron and oxygen. It is commonly used in various industrial applications, including the production of pigments, cement, and ceramics. There are several synonyms for this compound, including rust, ferric oxide, hematite, and magnetite. Rust is the most common synonym used to refer to iron oxide, which is the reddish-brown coating formed on iron when exposed to air and moisture. Ferric oxide is another synonym widely used in the chemical industry. Hematite and magnetite are two types of iron oxide minerals that are found in nature and have industrial applications, such as in the production of steel and fertilizers.