mineral

Potassium Feldspar

K-Feldspar (KAlSi3O8)

Hardness: 6 on Mohs scale; Color: Pink, salmon, or flesh-colored; Luster: Vitreous to pearly; Crystal structure: Monoclinic or Triclinic; Cleavage: Two directions at 90 degrees; Specific Gravity: 2.55-2.63.

Hardness: 6 on Mohs scale
Color: Pink, salmon, or flesh-colored
Luster: Vitreous to pearly

Identified June 2, 2026More mineral →

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Physical properties

Formation & geological history

Commonly forms in igneous rocks like granite and syenite through the cooling of magma, and in metamorphic rocks like gneiss. Found in various geological ages ranging from Precambrian to Cenozoic.

Uses & applications

Used in the manufacturing of glass and ceramics (porcelain), as a mild abrasive in scouring powders, and occasionally as a gemstone (Moonstone variant).

Geological facts

Feldspar is the most abundant mineral group in the Earth's crust, making up about 60% of its composition. Orthoclase is a common member of this group.

Field identification & locations

Identify by its distinctive pinkish color and two planes of cleavage at right angles. It is a primary constituent of pink granite commonly found in mountain ranges and continental crust exposures worldwide.