Cochise College          Photos of Minerals

                          Geology Home Page                

                          Roger Weller, geology instructor

                                  copyright 2006-R.Weller

Mineral Information on:

Chemical Group:    sulfide

Chemical Formula:   

Color: pale bronze-yellow, darkens on exposure to air          

Streak:  grayish black to brownish black


Hardness:  6 to 6.5        Specific Gravity:  4.89         Fracture:  uneven

Cleavage: (101), distinct


Crystal Forms:  Orthorhombic system
     Twinning is quite common and produces "cockscomb structures".
      May also occur as shiny, flat disks that form betwwen layers of shale.

Mineral Associations:  galena and sphalerite

Identifying Characteristics:  crystal shape (cockscomb)


Occurrences: found in near surface environments; less stable than pyrite

Toxicity:      when-swallowed- moderate          when inhaled- moderate

Additional Information: