A member of the plagioclase feldspar group and the Na-rich end member of the albite-anorthite series, this mineral is one of the rock-forming minerals. It is found in felsic plutonic rocks. Its name comes from the Latin word meaning "white," alluding to its usual color. As with all plagioclase feldspars, this mineral will display twinning striations on a cleavage face.

Mineral Photos courtesy of R.Weller/Cochise College