Iron(III) oxide

Iron(III) oxide or ferric oxide is the <a href="/facts/Inorganic_compound/TfFfzxSz">inorganic compound</a> with the formula Fe2O3. It occurs in nature as the mineral <a href="/facts/Hematite/716YBzGr">hematite</a>, which serves as the primary source of iron for the steel industry. It is also known as red iron oxide, especially when used in <a href="/facts/Pigment/I3clCYkF">pigments</a>.
It is one of the three main <a href="/facts/Oxide/DXtoVe1C">oxides</a> of <a href="/facts/Iron/DkICCKIC">iron</a>, the other two being <a href="/facts/Iron(II)_oxide/H9V7S3MG">iron(II) oxide</a> (FeO), which is rare; and <a href="/facts/Iron(II%2cIII)_oxide/8VzDaSxu">iron(II,III) oxide</a> (Fe3O4), which also occurs naturally as the mineral <a href="/facts/Magnetite/SVxoGUs2">magnetite</a>. 
Iron(III) oxide is often called <a href="/facts/Rust/sajUmaz8">rust</a>, since rust shares several properties and has a similar composition; however, in chemistry, rust is considered an ill-defined material, described as hydrous ferric oxide.
Ferric oxide is readily attacked by even weak <a href="/facts/Acid/FySU18n1">acids</a>. It is a weak <a href="/facts/Oxidising_agent/1FQzB8pQ">oxidising agent</a>, most famously when reduced by <a href="/facts/Aluminium/7wmR8jYE">aluminium</a> in the <a href="/facts/Thermite/vIbVld9Y">thermite</a> reaction.

Iron(III) oxide open-in-new

Iron(III) oxide