Fe2O

Fe2O is a chemical formula that can represent several iron oxide compounds. The most common and stable form is iron(II) oxide, also known as ferrous oxide, with the chemical formula FeO. In this compound, iron has an oxidation state of +2. Iron(II) oxide is a black solid and is insoluble in water. It can be formed by the incomplete oxidation of iron at high temperatures. Another less common interpretation of Fe2O could refer to a hypothetical or unstable diatomic molecule of iron and oxygen, but this is not a recognized stable compound. The empirical formula for iron(II,III) oxide, also known as magnetite, is Fe3O4, which can be thought of as a combination of FeO and Fe2O3, but Fe2O itself is not the standard representation for this mineral. Therefore, in most chemical contexts, Fe2O would be understood to represent iron(II) oxide, FeO, although the numerical subscript '2' for iron and '1' for oxygen is unconventional. The commonly encountered iron oxides are FeO (iron(II) oxide), Fe2O3 (iron(III) oxide), and Fe3O4 (iron(II,III) oxide).