Wüstite

oxide

hedenbergite

Formula: FeO
Simple oxide
Hardness: 5 to 5½
Colour: black
Environments:

Metamorphic environments

Wüstite may be found in kimberlite and basalt

Alteration

Wüstite is formed as an alteration product of other iron-bearing minerals at high temperatures in a highly reducing environment.

hematite, wüstite, quartz and calcite to andradite, hedenbergite, magnetite and CO2
If wüstite, FeO, is also introduced hedenbergite and magnetite may form in addition to andradite:
2Fe2O3 + 2FeO + 5SiO2 + 4CaCO3 → Ca3Fe3+2(SiO4)3 + CaFe2+Si2O6 +Fe2+Fe3+2O4 +4CO2

Back to Minerals