Cochise College          Photos of Minerals

                          Geology Home Page                

                          Roger Weller, geology instructor

                                  copyright 2006-R.Weller

Mineral Information on:

Chemical Group:    tungstate

Chemical Formula:  

Color:  dark gray, brownish black            Streak:   nearly black

Hardness:   5 to 5.5         Specific Gravity:  7 to 7.5           Fracture:  uneven

Cleavage:   (010) perfect          Tenacity:  brittle

Luster:   sub-metallic       Transparency:  opaque


Crystal Forms:  Monoclinic system
    Forms tabular and prismatic crystals

Mineral Associations: found in granite and pegmatites; sometimes occurs with cassiterite.

Identifying Characteristics:

Uses:  tungsten ore

Occurrences:  Nevada, South Dakota; China

Toxicity:      when-swallowed-               when inhaled-

Additional Information: