Mica Photos       
Cochise College               
Photos of Minerals
Geology Home Page

Roger Weller, geology instructor

wellerr@cochise.edu     copyright 2010-R.Weller 

biotite book
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                                                                                                                                             biotite2
Photo is copyright free for non-commercial educational uses.
Just credit photo to R.Weller/Cochise College.