mineral

Microcline (Potassium Feldspar)

Microcline (KAlSi3O8)

AI-generated identification · may be incorrect

Hardness: 6.0-6.5 (Mohs scale); Color: Pink to orange-red; Luster: Vitreous to pearly; Crystal structure: Triclinic; Cleavage: Two directions at nearly 90 degrees; Specific gravity: 2.54-2.57

Hardness: 6
Color: Pink to orange-red
Luster: Vitreous to pearly

Identified July 18, 2026More mineral →

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Physical properties

Hardness: 6.0-6.5 (Mohs scale); Color: Pink to orange-red; Luster: Vitreous to pearly; Crystal structure: Triclinic; Cleavage: Two directions at nearly 90 degrees; Specific gravity: 2.54-2.57

Formation & geological history

Commonly forms in plutonic igneous rocks like granite and pegmatites, as well as in metamorphic rocks like gneiss. It crystallizes during the slow cooling of silica-rich magma or through regional metamorphism.

Uses & applications

Used in the manufacture of glass and ceramics (as a flux), as a filler in paints and plastics, and occasionally as a gemstone (Amazonite variety) or for landscaping.

Geological facts

Microcline is a member of the feldspar group, which makes up about 60% of the Earth's crust. The pink variety is a hallmark component of pink granites found worldwide.

Field identification & locations

Identified in the field by its distinct pink/salmon color, blocky cleavage, and hardness that can scratch glass but is scratched by quartz. Common in granite outcrops and gravel deposits.