Definition from Wiktionary, the free dictionary
- (mineralogy) Potassium aluminum silicate, KAlSi3O8, a common feldspar of igneous, plutonic, and metamorphic rocks. Orthoclase is the main feldspar of pegmatite occurrences, where it is most commonly flesh-colored. Orthoclase is used in the ceramic and glass industries and as a decorative gravel.
potassium aluminum silicate