mineral

Potassium Feldspar (Microcline / Orthoclase)

KAlSi3O8

AI-generated identification · may be incorrect

Hardness: 6 on Mohs scale; Color: Salmon pink, flesh-red, or reddish-orange; Luster: Vitreous to pearly; Cleavage: Two directions at nearly 90 degrees; Crystal System: Triclinic or Monoclinic

Hardness: 6 on Mohs scale
Color: Salmon pink, flesh-red, or reddish-orange
Luster: Vitreous to pearly

Identified July 26, 2026More mineral →

Explore Potassium Feldspar (Microcline / Orthoclase) in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 6 on Mohs scale; Color: Salmon pink, flesh-red, or reddish-orange; Luster: Vitreous to pearly; Cleavage: Two directions at nearly 90 degrees; Crystal System: Triclinic or Monoclinic

Formation & geological history

Formed during the crystallization of felsic igneous rocks such as granite and pegmatites, as well as in high-grade metamorphic rocks.

Uses & applications

Used in glassmaking, ceramics, enamelware, and as an abrasive. High-purity specimens are collected for educational rock kits.

Geological facts

Feldspars make up around 60% of Earth's continental crust. Despite the grid label beneath it reading 'JASPER', the physical cleavage, pearly luster, and crystalline structure show this piece is actually Potassium Feldspar (placed in the Feldspar/Jasper card area).

Field identification & locations

Identified in the field by its distinct salmon-pink color, blocky cleavages at 90-degree angles, and hardness of 6 (scratches glass). Found globally in granitic pegmatites.