Cochise College          Photos of Minerals

                          Geology Home Page                

                          Roger Weller, geology instructor

                                  copyright 2006-R.Weller

Mineral Information on:

Chemical Group:   arsenide

Chemical Formula: 
CoAs3 to (Co,Ni)As3

Color:  tin-white to steel-gray, tarnishes iridescent to grayish

Streak:  grayish-black           Luster:  metallic


Hardness:  5.5 to 6                 Specific Gravity:  5.7 to 6.8                

Fracture:  granular and uneven

Cleavage:  indistinct


Crystal Forms and Habits:  Isometric system- pyritohedral
     Commonly massive

Mineral Associations:

Identifying Characteristics:

Uses:  cobalt and nickel ore


Toxicity:      when-swallowed-                            when inhaled-

Additional Information: