Cochise College          Photos of Minerals

                          Geology Home Page                

                          Roger Weller, geology instructor

                          wellerr@cochise.edu
                                  copyright 2006-R.Weller
 

Mineral Information on:
cassiterite

Chemical Group:    oxide

Chemical Formula:   
SnO2

Color: yellow, red-brown, brown-black                    

Streak:  white, grayish, brownish

 

Hardness:  6 to 7         Specific Gravity:   6.8 to 7.1                 

Fracture:  subconchoidal to uneven

Tenacity:  brittle

Cleavage:  2 directions, one perfect and the other imperfect

 

Crystal Forms and Habits:  Tetragonal system
     Cassiterite commonly forms twinned crystals (contact and penetration twins).
     Crystals may also be needle-like.
     In massive form, occurs  in botryoidal nodules with concentric banding (wood tin).

Mineral Associations:

Identifying Characteristics:  high specific gravity and hardness

Uses:  tin ore

Occurrences: 

Toxicity:      when-swallowed- low         when inhaled- moderate

Additional Information: