Transparency crystals are translucent, but usually translucent to opaque. Crystals have a nearly rectangular or square cross-section with slightly slanted dome and pinacoid terminations. Twinning is common. Crystals can be twinned according to the Albite, Pericline, Carlsbad, Manebach and Baveno laws. Microcline can be found as a major rock forming component in granites, syenites and in metamorphic gneisses.
Cleavage is perfect in one and good in another direction forming nearly right angled prisms.
Fracture is conchoidal. Hardness is 6 - 6.5. Streak is white. Associated Minerals are quartz , muscovite and plagioclase feldspars . Lamellar twinning may cause a grooved effect on cystal and cleavage surfaces that appear as striations.