A rock-forming potassium feldspar mineral, microcline was discovered in 1830 in Norway. The name comes from the Greek words meaning "little" and "to incline," in allusion to the small departure from monoclinic symmetry. It is found in plutonic felsic rocks, and in pegmatites, where it may be intimately intergrown with quartz forming graphic granite. The green variety is called Amazon stone.

Mineral Photos courtesy of R.Weller/Cochise College