A feldspar rich in potassium; specifically each of the three minerals orthoclase, microcline, and sanidine, which have the formula KAlSi₃O₈; these minerals collectively.
Origin
Late 19th century; earliest use found in Science.
Definition of potassium feldspar in US English:
potassium feldspar
noun
Mineralogy
A feldspar rich in potassium; specifically each of the three minerals orthoclase, microcline, and sanidine, which have the formula KAlSi₃O₈; these minerals collectively.