Iron oxide

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1 Iron oxides
2 Iron hydroxides
3 References

Ferruginous redirects here. For the bird, see Ferruginous Hawk

Altogether there are 16 known iron oxides.<ref>Cornell, RM, Schwertmann, U (2003). The iron oxides: structure, properties, reactions, occurrences and uses. Wiley VCH. ISBN 3-527-30274-3.</ref>

These compounds are either oxides (Hematite, Magnetite, Maghemite, β-Fe₂O₃, ε-Fe₂O₃, Wüstite), or hydroxides and oxide-hydroxides (Goethite, Lepidocrocite, Akageneite, Schwertmannite, Feroxyhyte, δ-FeOOH, high pressure FeOOH, Ferrihydrite, Bernalite, Fe(OH)₂, green rusts).

Some of these oxides are used in ceramic applications, particularly in glazing. Iron oxides, along with oxides of other metals, provide the colours in some glazes after being fired at a high temperature. They are also used as pigments (see Category:Iron oxide pigments).

[edit] Iron oxides

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Iron(II) oxide or ferrous oxide (FeO) The black-coloured powder in particular can cause explosions as it readily ignites.

Iron(III) oxide or ferric oxide (Fe₂O₃) known in its natural state as rouge or hematite (also 'haematite'), but also purified for use as a coating in magnetic audio and computer media, where it is known as ferric oxide. In a dry or alkaline environment it can cause passivation and inhibits rust. It is also a component of rust.

Iron(II,III) oxide or ferrous ferric oxide (Fe₃O₄), better known as the black-coloured mineral magnetite or lodestone also seen on Mars. Also a main source of iron, magnetite is an iron ore. This form of iron oxide tends to occur when iron corrodes underwater, and so is often found inside tanks or below the waterline of ships.

[edit] Iron hydroxides

Iron(II) hydroxide Fe(OH)₂. green colour.

Iron(III) oxide-hydroxide FeO(OH) found as the mineral goethite. Red-brown colour. Also found as the minerals siderogel, limonite and feroxyhyte. There is a variant known as lepidocrocite.