Maghemite
A magnetic iron oxide with the spinel structure, formed by oxidation of magnetite and metal.
Key facts
- Formula
- γ-Fe2O3
- Family
- Oxides
- Crystal system
- Cubic
What it is
Maghemite has the same formula as hematite but the spinel structure of magnetite, with some iron sites left empty. It is strongly magnetic. Its name joins magnetite and hematite.
Where it is found
In meteorites it forms in fusion crusts, in rusted metal and as rims on magnetite in weathered stones. It is common in micrometeorites and cosmic spherules, which are heated and oxidised as they pass through the air.
How it is recognised
It is brown to black and magnetic. It is distinguished from magnetite by X-ray diffraction or by its higher oxidation state.
Did you know?
Did you know?
Maghemite is used in magnetic recording tape.
Did you know?
It slowly turns into hematite when heated to a few hundred degrees.