Mica Photos       
Cochise College               
Photos of Minerals
Geology Home Page

Roger Weller, geology instructor

wellerr@cochise.edu     copyright 2010-R.Weller 

muscovite and biotite
Muscovite is KAl3Si3O10(OH)2
Biotite is K(Mg,Fe)3AlSi3O10(OH)2
Muscovite (white mica) and biotite (black mica) are really two distinct minerals. 
In this specimen both micas are present and there is no overlap in composition.


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