Iron(III) oxide or ferric oxide is the inorganic compound with the formula Fe₂O₃. It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO), which is rare, and iron(II,III) oxide (Fe₃O₄), which also occurs naturally as the mineral magnetite. As the mineral known as hematite, Fe₂O₃ is the main source of the iron for the steel industry. Fe₂O₃ is ferromagnetic, dark red, and readily attacked by acids. Iron(III) oxide is often called rust, and to some extent this label is useful, because rust shares several properties and has a similar composition. To a chemist, rust is considered an ill-defined material, described as hydrated ferric oxide.

Eisen(III)-oxid ist ein stabiles Oxid des Eisens. Es ist unter anderem ein Bestandteil des Rostes und verursacht dessen Farbe.

La hematita, hematites u oligisto es un mineral compuesto de óxido férrico (Fe₂O₃) y constituye una importante mena de hierro ya que en estado puro contiene el 70 e este metal.

El óxido de hierro (III) u óxido férrico tiene varias formas estructurales:

α-estructura del corindón.

γ-estructura tipo espinela.

Rauta(III)oksidi on raudan yhdiste hapen kanssa, jossa happi esiintyy hapetusluvulla -II ja rauta +III. Näin muodostuva yhdiste on Fe₂O₃. Se voidaan myös nimetä dirautatrioksidiksi tai ferrioksidiksi. Rauta(III)oksidi on yksi raudan useista happiyhdisteistä ja sillä on paramagneettisia ominaisuuksia.