Cochise College          Photos of Minerals

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                          Roger Weller, geology instructor

                          [email protected]
                                  copyright 2006-R.Weller
 

Mineral Information on:
colemanite

Chemical Group:    borate

Chemical Formula:    Ca₂B₆O₁₁.5H₂O

Color:  colorless, white, yellowish, grayish              Streak:   white

Hardness:  4.5          Specific Gravity:  2.42          

Fracture:   uneven        Tenacity:  brittle
 

Luster:  vitreous      Transparency:  transparent to translucent

Cleavage:  (010) perfect, (001) distinct

Crystal Forms:  Monoclinic system
        Often massive, granular

Mineral Associations:   other borate minerals

Identifying Characteristics:

Uses:  used in producing borate compounds

Occurrences:  California borax deposits

Toxicity:      when-swallowed- high         when inhaled- moderate

Additional Information: