AM_Anorthoclase_3 Formula: (Al Si3) (Na.75 K.25) O8 Name: Anorthoclase Unit cell: 8.314 12.973 7.15 90.0 116.135 90.0 , V=692.33 Space group: C12/M1 (12)

Harlow G E , American Mineralogist , 67 (1982) p.975-996, The anorthoclase structures: The effects of temperature and composition, Mt. Gibele, Or = 22.3, T = 510 deg C, feldspar