Hematite


Composition: Fe2O3
Crystal System : Trigonal
Colours: Steel-grey, black, brown-red, red
Lustre : Metallic, dull, earthy
Hardness (H) : 5.0-6.5
Specific Gravity (S.G) : 5.26

Distribution

Common. Present in all three oxidation zones.

Occurrence

  • Hypogene
  • Supergene
  • Country Rock
  • 1st Oxidation Zone
  • 2nd Oxidation Zone
  • 3rd Oxidation Zone

Paragenetic and General Notes

Pinch and Wilson (1977) report hematite as "black crusts of very small, sometimes translucent, red, lustrous crystals", as "botryoidal 'kidney ore'", and as "octahedral 'martite' pseudomorphs after magnetite to about 1 cm in size."

There is a tendency to use the name "hematite" for undifferentiated oxides and hydroxides of iron (i.e. limonite).

Hematite is reported to form pseudomorphs after the following minerals:  magnetite (rare).