Mica Photos       
Cochise College               
Photos of Minerals
Geology Home Page

Roger Weller, geology instructor

wellerr@cochise.edu     copyright 2010-R.Weller 

biotite book-2
Biotite is K(Mg,Fe)3AlSi3O10(OH)2
Biotite is also known as black mica.  It can be peeled off of a large crystal in thin layers
but with more difficulty than peeling muscovite (white mica).  Biotite does not have
economic value because it lacks the transparency and electrical insulating properties
found in muscovite.

mica                                                                                                                                                2188
Photo is copyright free for non-commercial educational uses.
Just credit photo to R.Weller/Cochise College.