Feldspar Photos  
Cochise College               
Photos of Minerals
Geology Home Page

Roger Weller, geology instructor

[email protected]     copyright 2016-R.Weller

 
labradorite-schiller
Labradorite is a plagioclase feldspar with a composition ranging from 50% to 70%

albite feldspar (the sodium end member of the plagioclase family) and 50% to 70%

anorthite (the calcium end member).  One of the special identifying characteristics

of labradorite is a spectacular display of colors when the mineral is viewed at certain

angles; this property is referred to as "schiller".  Schiller is largely due to the

interference of light caused by the reflection from thin lamellar inclusions of various

minerals.  Blue and green are the most common colors, but red, yellow, and
gray are also common.
 

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