mineral
Potassium Feldspar
K-Feldspar (Orthoclase/Microcline) KAlSi3O8
Hardness: 6 (Mohs); Color: Salmon pink to reddish-orange; Luster: Vitreous to pearly; Crystal structure: Monoclinic or Triclinic; Cleavage: Two directions at 90 degrees; Specific Gravity: 2.5-2.6
- Hardness
- 6 (Mohs)
- Color
- Salmon pink to reddish-orange
- Luster
- Vitreous to pearly
Identified More mineral →
Explore Potassium Feldspar in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6 (Mohs); Color: Salmon pink to reddish-orange; Luster: Vitreous to pearly; Crystal structure: Monoclinic or Triclinic; Cleavage: Two directions at 90 degrees; Specific Gravity: 2.5-2.6
Formation & geological history
Forms primarily in igneous rocks like granite and syenite through the cooling of silica-rich magma; also found in metamorphic rocks like gneiss and as clasts in sedimentary rocks.
Uses & applications
Used in the manufacture of glass and ceramics, as a filler in paints and plastics, and occasionally as a gemstone (moonstone or sunstone varieties).
Geological facts
Feldspars are the most abundant mineral group in Earth's crust, making up about 60% of terrestrial rocks. The pink color in this specimen is often due to trace amounts of iron or hematite inclusions.
Field identification & locations
Identify by its distinctive salmon-pink color, blocky cleavage planes that reflect light, and its ability to scratch glass but be scratched by quartz. Common in granitic terrains worldwide.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock
Granite
Granite (Phaneritic intrusive igneous rock)
igneous