Feldspar is an aluminosilicate mineral of alkali metals such as potassium, sodium and calcium or alkaline earth metals, also known as feldspar minerals. Potassium feldspar (K2O Al2O3 6SiO 2) is also commonly known as orthoclase. Liaoning talc powder potassium feldspar series is mainly orthoclase, microcline, striped feldspar and so on.