Microcline is an important igneous rock-forming tectosilicate mineral. It is a potassium-rich alkali feldspar and contains minor amounts of sodium.

Microcline is a common, potassium-rich mineral that forms igneous rocks, such as granite, and is also used in industry to make porcelain, glass, and ceramics

Microcline may be clear, white, pale-yellow, brick-red, or green; it is generally characterized by cross-hatch twinning that forms as a result of the transformation of monoclinic orthoclase into triclinic microcline.