Blocky Microcline crystals with clear Quartz crystals.
CHEMISTRY KAlSi3O8 Potassium aluminum silicate
CRYSTALLOGRAPHY Triclinic
CRYSTAL GROWTH AND HABITS Microcline commonly forms elongate prismatic crystals, sometimes in large cleavable masses (up to 100's of tons). It commonly has perthitic intergrowths producing a banded appearance. It is also granular to massive.
COLOR AND OTHER OPTICAL PROPERTIES Microcline is white, yellow white, reddish and green to bluish. It is transparent to translucent.
HARDNESS 6 - 6.5
SPECIFIC GRAVITY 2.54 - 2.57
LUSTER Vitreous
STREAK White
BREAKABILITY Microcline has very good cleavage in 2 directions at nearly 90o producing blocky fragments. It has an uneven fracture and is brittle.
OCCURRENCE Microcline is common in intrusive igneous rocks like granite, granitic pegmatites, syenites, and in hydrothermal veins. It is also found in the metamorphic rock greenschist and in the amphibolite facies.
ASSOCIATED MINERALS Quartz, sodium rich Plagioclase, Muscovite, Biotite