Do you really want to send Webster 1913 a message saying you like their work?
A*nor"tho*clase (?), n. [Gr. &?; priv. + orthoclase.] (Min.)
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