A mineral consisting chiefly of aluminum and silica. feldspath.
A widely distributed crystalline mineral, which consists of silica, alumina, and potash, and is a constituent part of granite, gneiss, mica, slate, porphyry, and most volcanic rocks.
n. [German] A crystalline mineral, somewhat vitreous in lustre, and breaking rather easily in two directions. It consists of silica, alumina, and potash:—also Felspar; feldspath.
