Definition of potassium feldspar in English:
potassium feldspar
noun
MineralogyA feldspar rich in potassium; specifically each of the three minerals orthoclase, microcline, and sanidine, which have the formula KAlSi₃ O₈; these minerals collectively.
Origin
Late 19th century; earliest use found in Science.
Are You Learning English? Here Are Our Top English Tips