mineral

Moonstone

Orthoclase and Albite (KAlSi3O8 / NaAlSi3O8)

Hardness: 6-6.5 (Mohs scale), Color: White, blue-white, or colorless with adularescence, Luster: Vitreous to pearly, Crystal structure: Monoclinic or Triclinic, Cleavage: Perfect in two directions.

Hardness: 6-6

Identified June 16, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 6-6.5 (Mohs scale), Color: White, blue-white, or colorless with adularescence, Luster: Vitreous to pearly, Crystal structure: Monoclinic or Triclinic, Cleavage: Perfect in two directions.

Formation & geological history

Formed in igneous and metamorphic rocks, specifically within pegmatites. It forms from two intergrown feldspar species that separate as the magma cools, creating alternating layers that scatter light.

Uses & applications

Primarily used in jewelry for cabochons, beads, and rings; also popular in ornamental carvings and as a collector's mineral.

Geological facts

The unique shimmering effect is called adularescence, caused by light scattering between layers of orthoclase and albite. It is the state gem of Florida to commemorate the moon landing.

Field identification & locations

Identify by looking for a milky appearance and a blue or white flash of light (adularescence) when tilted. Found commonly in Sri Lanka, India, and Myanmar.

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