Mica Photos       
Cochise College               
Photos of Minerals
Geology Home Page

Roger Weller, geology instructor

[email protected]     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.
 

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