Mineral description : Pyrolusite

Pyrolusite from Harstigen.

Mineral class Oxides : Pyrolusite - Manganite group
Chemical formula MnO2
Crystal system Tetragonal
Habitus Dendritic or massive fibric aggregates. Crystals are prismatic but very rare.
Cleavage Perfect, uneven fracture.
Hardness 2 (-6.5)
Density 5.2
Color Matte black to dark gray.
Streak Black to bluish black.
Luster Metallic to earthy.
Description  
Occurance As dendritic forms in Dolomite cracks.
As massive fibric aggregates.
Pyrolusite is a secondary mineral in manganese occurances.
Also forms asnodules in the oceans and as precipitate in lakes.
Associates  
Notes Soluble in hydrochloric acid.
Locations
    Pyrolusite is a less common manganese ore in Sweden.
  • Harstigen, Persberg. As dendrites in dolomite cracks.
  • Bölet manganese mine, Undenäs, Västergötland.
  • Spexaryd manganese mine, south Jönköping.

To silicate index.
Mineral group index.
Main index.

If you have some questions, suggestions or comments you are welcome to write me a line or two.


axelsson@acc.umu.se
To my homepage.
Last changed : 1998-03-07