Word Study
anorthoclase
CIDE DICTIONARY
anorthoclase, n. [Gr. priv. + orthoclase.].
A feldspar closely related to orthoclase, but triclinic. It is chiefly a silicate of sodium, potassium, and aluminium. Sp. gr., 2.57 -- 2.60. [Webster 1913 Suppl.]
For further exploring for "anorthoclase" in Webster Dictionary Online