Cochise College          Photos of Minerals

                          Geology Home Page                

                          Roger Weller, geology instructor

                          wellerr@cochise.edu
                                  copyright 2006-R.Weller
 

Mineral Information on:
thomsonite


Chemical Group:    silicate  (zeolite)

Chemical Formula:   
2(Ca,Na2)Al2Si2O8.5H20

Color: white, reddish-green, brown               Streak:  uncolored

 

Hardness:  5 to 5.5               Specific Gravity:  2.3 to 2.4                

Fracture:    uneven to sub-conchoidal             Luster:  vitreous to pearly

Cleavage:  (010) and (100)           Tenacity:  brittle

 

Crystal Forms:  Orthorhombic system
     Crystal rare

Habits:  Commonly in radiating spherical concretions; also compact

Mineral Associations:   found in amygdaloidal basalt

Identifying Characteristics:

Uses:  as a gemstone

Occurrences:  Lake Superior region

Toxicity:      when-swallowed-                            when inhaled-

Additional Information: