mineral
Feldspar (Orthoclase)
Potassium Feldspar (KAlSi3O8)
AI-generated identification · may be incorrectHardness: 6 (Mohs scale), Color: Salmon pink to orange-tan, Luster: Vitreous to pearly, Crystal Structure: Monoclinic, Cleavage: Two directions at 90 degrees, Specific Gravity: 2.55-2.63
Identified More mineral →
Explore Feldspar (Orthoclase) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6 (Mohs scale), Color: Salmon pink to orange-tan, 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 igneous rocks like granite and pegmatites through the cooling of magma, as well as in metamorphic rocks like gneiss. Found globally in continental crust.
Uses & applications
Used in glassmaking and ceramics to lower melting temperatures, as an abrasive in scouring powders, and occasionally as a gemstone (monstone/sunstone varieties).
Geological facts
Feldspars are the most abundant group of minerals in the Earth's crust, making up about 60% of terrestrial rocks. The name is derived from the German 'Feldspat'.
Field identification & locations
Identify by its blocky pink appearance and distinct cleavage planes that reflect light. It is common in gravel and weathered granite outcrops.
More like this
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