Microcline rates a 6 to 6.5 on the Moh’s hardness scale
. It has a vitreous
to silky luster, and can sometimes be dull if weathered. Crystals are usually translucent to opaque, but can also be perfectly translucent. These translucent stones are of more value. A form of alkali feldspar
, microcline may be many different colors: colorless, white, off-white, brown, yellow, pink, red, gray, green, or blue green. Stones display no pleochroism
. Microcline is found in a number of different kinds of metamorphic rocks. It can be found in granites, granite pegmatites, hydrothermal veins, and in many schists and gneisses. It is also found as grains in sedimentary
rocks. It is most widely found in the form of minute crystals in rocks, however large crystals can be found specifically in pegmatites. In fact, microcline can form the largest known crystals of any mineral, and large specimens come to market often.