Cochise College          Photos of Minerals

                          Geology Home Page                

                          Roger Weller, geology instructor

                          wellerr@cochise.edu
                                  copyright 2006-R.Weller
 

Mineral Information on:
pyrolusite

Chemical Group:    oxide

Chemical Formula:   
MnO2

Color:  light to dark steel-gray to iron gray                   Streak:  black

Luster:  metallic

 

Hardness:  6 to 6.5 in crystals          Specific Gravity:  5.06                 

Fracture:  uneven            Tenacity:  brittle

Cleavage: one direction     Transparency:  opaque

 

Crystal Forms and Habits:  Tetragonal system
    Rarely occurs as prismatic crystals.
    Common forms: massive, concretions, coatings, powdery, dendrites

Mineral Associations:

Identifying Characteristics:  Forms dendritic patterns on cracked surfaces that resemble plants.

Uses:  manganese ore

Occurrences: 

Toxicity:      when-swallowed- moderate            when inhaled- high

Additional Information: