mineral
Feldspar (Orthoclase / Microcline) with Quartz
KAlSi3O8 (Potassium Feldspar / Orthoclase)
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
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Physical properties
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.
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.
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