mineral

Moonstone (specifically White Moonstone or Girasol Quartz)

Potassium aluminum silicate (KAlSi3O8)

Hardness: 6-6.5 (Mohs scale), Color: opalescent white to colorless, Luster: Vitreous to Pearly, Crystal structure: Monoclinic, Cleavage: Perfect two-directional, Specific Gravity: 2.56-2.59

Hardness: 6-6

Identified April 26, 2026More mineral →

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Physical properties

Hardness: 6-6.5 (Mohs scale), Color: opalescent white to colorless, Luster: Vitreous to Pearly, Crystal structure: Monoclinic, Cleavage: Perfect two-directional, Specific Gravity: 2.56-2.59

Formation & geological history

Formed from intergrowths of two types of feldspar (orthoclase and albite) that separate into layers as the magma cools. These layers scatter light, creating the 'adularescence' effect.

Uses & applications

Primary use is in jewelry (beads, cabochons, and rosaries) and as a birthstone (June). Also popular in metaphysical and collector circles.

Geological facts

Ancient Romans believed moonstone was formed from frozen beams of moonlight. It is the state gem of Florida, despite no moonstone naturally occurring there (it was named to commemorate the moon landings).

Field identification & locations

Identify by its unique glow (adularescence) that moves across the surface. Beads like these should feel cold to the touch; if they are warm or light, they may be plastic or glass imitations.

Other mineral specimens

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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