mineral

Feldspar (specifically Orthoclase)

Potassium Aluminum Silicate (KAlSi3O8)

AI-generated identification · may be incorrect

Hardness: 6 on Mohs scale; Color: Flesh-pink to salmon; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Two directions at 90 degrees; Specific Gravity: 2.55-2.63

Hardness: 6 on Mohs scale
Color: Flesh-pink to salmon
Luster: Vitreous to pearly

Identified June 28, 2026More mineral →

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Physical properties

Hardness: 6 on Mohs scale; Color: Flesh-pink to salmon; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Two directions at 90 degrees; Specific Gravity: 2.55-2.63

Formation & geological history

Forms primarily in intrusive and extrusive igneous rocks like granite and rhyolite, as well as some metamorphic rocks. It crystallizes from cooling magma at high temperatures.

Uses & applications

Used in the manufacture of glass and ceramics, as a filler in paints and plastics, and as an abrasive in scouring powders. Gem-quality varieties (like Moonstone) are used in jewelry.

Geological facts

Feldspar is the most abundant mineral group in the Earth's crust, making up about 60% of its composition. The pink color in common granite is usually due to Orthoclase feldspar.

Field identification & locations

Identify by its distinct pinkish color and right-angle cleavage planes. It cannot be scratched by a steel nail but can be scratched by quartz. Common globally in granitic terrains.