mineral

Moonstone

Orthoclase (KAlSi3O8) with Albite (NaAlSi3O8)

AI-generated identification · may be incorrect

Hardness: 6.0-6.5 on Mohs scale. Color: Colorless to white/pearly with blue or white schiller. Luster: Vitreous to pearly. Crystal structure: Monoclinic. Cleavage: Perfect in two directions. Specific gravity: 2.56-2.59.

Hardness: 6
Color: Colorless to white/pearly with blue or white schiller
Luster: Vitreous to pearly

Identified July 6, 2026More mineral →

Explore Moonstone in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Formed in igneous or metamorphic environments when feldspar minerals cool and separate into alternating layers of orthoclase and albite. This layered structure causes the characteristic adularescence (glow).

Uses & applications

Primarily used in jewelry as cabochons, beads, and carvings. Also highly valued by gemstone collectors and for metaphysical purposes.

Geological facts

The optical phenomenon called adularescence creates a billowy light that appears to float across the surface. Moonstone is the birthstone for June and is the state gem of Florida (commemorating the Moon landings).

Field identification & locations

Identified in the field by its pearly luster and distinctive adularescent glow when rotated under light. Commonly found in Sri Lanka, India, Myanmar, and Madagascar. Look for the 'blue flash' in higher quality specimens.