Cochise College          Photos of Minerals

                          Geology Home Page                

                          Roger Weller, geology instructor

                                  copyright 2006-R.Weller


Mineral Information on:

Chemical Group:   oxide

Chemical Formula:  (Fe,Zn,Mn)O.(Fe,Mn)2O3

Color:  iron black                 Streak:  reddish brown or black


Hardness:   5.5 to 6.5              Specific Gravity:     5.07 to 5.22                 

Fracture:    conchoidal to uneven

Cleavage:  octahedral parting


Crystal Forms: Isometric system
     Forms octahedrons that are usually rounded

Mineral Associations: willemite, zincite, and calcite

Identifying Characteristics: rounded black octahedrons (almost appears melted)

Uses:  zinc ore

Occurrences:  Franklin, New Jersey

Toxicity:      when-swallowed-                            when inhaled-

Additional Information: