Plagioklaasit
Plagioklaasit, also known as plagioclase, is a major group of feldspar minerals defined by a continuous solid solution between albite (NaAlSi3O8) and anorthite (CaAl2Si2O8). The series includes oligoclase, andesine, labradorite, bytownite, and the end-members albite and anorthite.
Plagioklaasit feldspars are tectosilicates with a framework of aluminosilicate tetrahedra. Most plagioclase minerals crystallize in the
Plagioklaasit is among the most abundant minerals in Earth's crust and occurs in felsic to mafic rocks,
Physical properties include a hardness of about 6–6.5, a specific gravity around 2.7, and two good cleavages