mineral
Orthoclase Feldspar
Potassium aluminum silicate (KAlSi3O8)
AI-generated identification · may be incorrectHardness: 6 (Mohs), Color: Pinkish-orange/tan, Luster: Vitreous to pearly, Crystal structure: Monoclinic, Cleavage: Two planes at 90 degrees, Specific gravity: 2.55-2.63
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Physical properties
Hardness: 6 (Mohs), Color: Pinkish-orange/tan, Luster: Vitreous to pearly, Crystal structure: Monoclinic, Cleavage: Two planes at 90 degrees, Specific gravity: 2.55-2.63
Formation & geological history
Formed through the cooling and crystallization of felsic magmas and in metamorphic rocks. Commonly found in granitic pegmatites.
Uses & applications
Major industrial ingredient in the manufacture of glass and ceramics (porcelain and glazes). Gem-quality varieties like moonstone are used in jewelry.
Geological facts
Orthoclase is one of the most common minerals in the Earth's crust. It is a defining mineral for level 6 on the Mohs scale of mineral hardness.
Field identification & locations
Identify in the field by its distinct pinkish/flesh color and 90-degree cleavage planes. It is abundant in continental mountain ranges and riverbeds containing granitic gravel.
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Other mineral specimens
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Tumbled granite
Granite, a coarse-grained felsic intrusive igneous rock
igneous
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Granite
Granite (Phaneritic intrusive igneous rock)
igneous