mineral

Feldspar (Orthoclase / Microcline) with Quartz

KAlSi3O8 (Potassium Feldspar / Orthoclase)

AI-generated identification · may be incorrect

Hardness: 6.0 on the Mohs scale. Color: Orangish-tan, pinkish-buff, to creamy white. Luster: Vitreous to dull/earthy due to weathering. Cleavage: Two directions at nearly 90 degrees. Specific Gravity: 2.56-2.59. Crystal system: Monoclinic or Triclinic.

Hardness: 6
Color: Orangish-tan, pinkish-buff, to creamy white
Luster: Vitreous to dull/earthy due to weathering

Identified July 25, 2026More mineral →

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Physical properties

Formation & geological history

Formed in intrusive igneous rocks, particularly pegmatites and granites, through slow crystallization of silica-rich magma. It often degrades into clay minerals upon weathering, giving it a rough, blocky surface texture.

Uses & applications

Feldspar is heavily used in industrial applications such as glassmaking, ceramics, enamel manufacture, and as a filler in paint, plastics, and rubber. High-quality crystalline specimens are collected by mineral enthusiasts.

Geological facts

Potassium feldspar is one of the most abundant mineral groups in the Earth's continental crust. Its distinct right-angle cleavage planes make it easy to identify even in weathered rock outcrops.

Field identification & locations

Look for blocky, geometric cleavage faces with a salmon-pink to yellowish-tan tone, often alongside quartz or mica. Commonly found in granitic mountainous regions and pegmatite deposits worldwide.