Cochise College          Photos of Minerals

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                          Roger Weller, geology instructor

                          [email protected]
                                  copyright 2006-R.Weller
 

Mineral Information on:
bytownite

Chemical Group:    silicate  (plagioclase feldspar)

Chemical Formula:      Bytownite is a mid-composition plagioclase feldspar 
     Bytownite ranges from 30% to 10% NaAlSi₃O₈ and 70% to 90% CaAl₂Si₂O₈.

Color: white, gray, reddish, greenish, yellowish, brown, colorless       Transparency:  transparent to translucent                   

Streak:  uncolored        Luster:  vitreous, pearly        Tenacity:  brittle

Hardness:  5 to 6             Specific Gravity:  2.60 to 2.75                  

Fracture:   uneven to conchoidal

Cleavage:  (001) perfect and (010) slightly less
    

Crystal Forms: Triclinic system
     Crystals prismatic
     Commonly shows polysynthetic (plagioclase) twinning.

Mineral habits:  massive, granular, coarse lamellar
    
Mineral Associations:  igneous rocks

Identifying Characteristics:   plagioclase twinning

Uses:

Occurrences: 

Toxicity:      when-swallowed- moderate              when inhaled- high

Additional Information: