mineral

Pink Feldspar (Orthoclase)

Orthoclase Feldspar (KAlSi3O8)

Hardness: 6.0 on Mohs scale; Color: Salmon pink to reddish-brown; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Two directions at 90 degrees; Specific Gravity: 2.55-2.63

Hardness: 6
Color: Salmon pink to reddish-brown
Luster: Vitreous to pearly

Identified May 4, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 6.0 on Mohs scale; Color: Salmon pink to reddish-brown; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Two directions at 90 degrees; Specific Gravity: 2.55-2.63

Formation & geological history

Formed primarily in intrusive igneous rocks like granite and syenite through the cooling of silica-rich magma or in metamorphic rocks like gneiss. This mineral is common across many geological eras.

Uses & applications

Extensively used in the manufacture of glass and ceramics, as a mild abrasive in scouring powders, and occasionally as a gemstone (moonstone variant) or for decorative aggregate.

Geological facts

Orthoclase is one of the ten defining minerals of the Mohs scale of mineral hardness. It is one of the most abundant minerals in the Earth's continental crust.

Field identification & locations

Identify in the field by its distinct salmon-pink color, blocky cleavage planes at right angles, and its ability to scratch glass but be scratched by quartz. Common in mountain ranges and granite outcrops.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral