Definition of microcline in English:



  • [mass noun] A green, pink, or brown crystalline mineral consisting of potassium-rich feldspar, characteristic of granite and pegmatites.

    • ‘Well-formed crystals of quartz, microcline, and albite typically line pocket walls.’
    • ‘Also associated with smoky quartz are microcline, fluorite, goethite (some as ‘onegite’), and topaz.’
    • ‘The pegmatite is composed of microcline, plagioclase and quartz with minor amounts of clinopyroxene, orthopyroxene, ilmenite and zircon.’
    • ‘They collected several pegmatite pockets in which topaz was associated with both clear and smoky quartz, microcline, albite, muscovite, fluorite, and cassiterite.’
    • ‘The aegirine was associated with aesthetic smoky quartz, microcline, and zircon.’


Mid 19th century: from German Microklin, from Greek mikros small + klinein to lean (because its angle of cleavage differs only slightly from 90 degrees).