Minerals

Composition

Curie/Neel temperature (˚C)

Mass susceptibility (´10⁻⁸ SI/kg)

Magnetite

Fe₃O₄

575 - 580

578

Maghemite

g-Fe₃O₄

unstable

500

Hematite

a-Fe₂O₃

675 - 680

25

Goethite

g-FeOH

120 - 130

0.5 - 1.5

Pyrrhotite

Fe7S8

320

0.1 - 20