Pyrolusite


Composition: MnO2
Crystal System : Tetragonal
Colours: Black, steel-grey
Lustre : Metallic, dull
Hardness (H) : 6.0-6.5
Specific Gravity (S.G) : 5.06
References:

Bartelke (1976)

Distribution

Common. Documented from the second oxidation zone (Weber, 1977). Probably also in the first (?) and third (?) oxidation zones.

Occurrence

  • Supergene
  • 1st Oxidation Zone
  • 2nd Oxidation Zone
  • 3rd Oxidation Zone

Paragenetic and General Notes

Powdery to acicular crystals and masses (Pinch and Wilson, 1977). As black coatings on cerussite and calcite; sometimes with (much rarer) coronadite, chalcophanite, and romanèchite (Gebhard, 1999).