Cochise College          Photos of Minerals

                          Geology Home Page                

                          Roger Weller, geology instructor

                          [email protected]
                                  copyright 2006-R.Weller
 

Mineral Information on:
corundum

Chemical Group:    oxide

Chemical Formula:    Al₂O₃

Color: gray, blue, pink, red, yellow, green, violet, black          Streak:  white

Luster: adamantine to vitreous

Transparency:  transparent to translucent

Hardness:   9        Specific Gravity:   4.0 to 4.1                  Fracture:

Cleavage: displays parting

Crystal Forms and Habits:  Trigonal system
   Most common form is a rough, barrel-shaped hexagonal prism

Mineral Associations:

Identifying Characteristics:  second hardest mineral

Uses:  an abrasive, if low quality
    If transparent and colorful, a gemstone: if red it is a ruby, other colors are sapphires.

Occurrences:   Ontario, Canada, also Burma and Montana 

Toxicity:      when-swallowed- low        when inhaled- moderate

Additional Information: