mineral

Moonstone (specifically White Moonstone/Adularia)

Potassium aluminum silicate ((K,Na)AlSi3O8)

AI-generated identification · may be incorrect

Hardness: 6-6.5 (Mohs scale); Color: White, colorless, or pearly; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Specific gravity: 2.56-2.59; Optical effect: Adularescence (a milky bluish sheen).

Hardness: 6-6
Color: White, colorless, or pearly
Luster: Vitreous to pearly

Identified April 3, 2026More mineral →

Explore Moonstone (specifically White Moonstone/Adularia) 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 and metamorphic rocks under specific cooling conditions where two types of feldspar (orthoclase and albite) separate into thin, alternating layers, causing light to scatter.

Uses & applications

Primarily used in jewelry as cabochons, rings, and pendants; also used by collectors and in metaphysical healing practices.

Geological facts

Ancient Romans and Greeks associated moonstones with their lunar deities. The phenomenon of its shimmering light is called adularescence, named after Mt. Adular in Switzerland, a famous source.

Field identification & locations

Identify by its characteristic soft, pearly sheen that moves across the surface as the stone is turned (adularescence). It has two directions of cleavage at nearly 90 degrees. Commonly found in Sri Lanka, India, and Myanmar.