Collection: Pyrolusite
Crystal system:
Pyrolusite crystallizes in the tetragonal crystal system. It typically shares the same crystal structure as rutile. Well formed crystals are rare. It usually occurs in massive,granular or columnar habits,or as distinctive dendritic patterns.
Mineral class-
Pyrolusite belongs to the oxide mineral class. Its chemical composition is magnesium dioxide.
Rock formation -
The mineral forms primarily through sedimentary processes and secondary weathering. It develops in highly oxidation environments.
Oxidation zones-
Formed when primary manganese bearing minerals undergo severe weathering and oxidation.
Sedimentary deposits-
Precipitated directly from water in shallow marine environments,bogs or lakes ,often forming nodules or beds.
Hydrothermal veins-
Deposited by low temperature hydrothermal fluids passing through fractures.
Hardness-
The MOHs hardness of pyrolusite is 6-6.5 for distinct crystals. However because it commonly occurs in aggregate,earthy or fibrous masses, it frequently exhibits an apparent hardness as low as 1-2 .which readily soils the fingers with a nock streak.
