Cochise College          Photos of Minerals

                          Geology Home Page                

                          Roger Weller, geology instructor

                          wellerr@cochise.edu
                                  copyright 2005-R.Weller
 

Mineral Information on:
alunite

Chemical Group:    sulfate

Chemical Formula:   
KAl3(SO4)2(OH)6

Color:  white, grayish, yellowish, reddish                    Streak:  white

 

Hardness:  3.5 to 4             Specific Gravity:  2.6 to 2.9                 

Fracture:  uneven to conchoidal

Cleavage:  rhombohedral, but rarely seen because of massive nature

 

Crystal Forms and Habits:  Trigonal system
     Usually massive

Mineral Associations:

Identifying Characteristics:

Uses:

Occurrences:  Colorado, Nevada, Utah

Toxicity:      when-swallowed- low              when inhaled- moderate

Additional Information:  Occurs in rocks that have been altered by sulfuric acid.