Description
The mineral albite is a sodium-aluminum tectosilicate with the chemical formula NaAlSi3O8. It is a plagioclase and belongs to the feldspars. White, gray, or light blue-green albite has a vitreous luster, a white streak color, perfect cleavage along the [001] crystal plane, and good [010] cleavage. Its average density is 2.62 and its hardness is 7. The crystal system is triclinic, and the mineral is neither radioactive nor magnetic. The name of the mineral albite is derived from the Latin albus, meaning "white." Albite is a very common feldspar in metamorphic and igneous rocks. It occurs primarily in pegmatites. It is the sodium endmember of the plagioclase series (albite-anorthite) and of the potassium feldspar series (albite-orthoclase). The type localities for albite have been designated as Amelia in Virginia, USA, and the Bourg d'Oisans and Isère in France.
