mineral

Moonstone

Orthoclase Feldspar (KAlSi3O8) or Albite mixtures

Hardness: 6.0-6.5 on Mohs scale; Color: Colorless to white, often with a blue or white sheen; Luster: Vitreous to pearly; Crystal Structure: Monoclinic; Cleavage: Perfect in two directions; Specific Gravity: 2.56-2.59

Hardness: 6
Color: Colorless to white, often with a blue or white sheen
Luster: Vitreous to pearly

Identified March 25, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of magma in igneous or metamorphic rocks (pegmatites). The visual effect (adularescence) occurs when two types of feldspar, orthoclase and albite, intergrow and separate into thin, alternating layers during cooling.

Uses & applications

Primarily used in jewelry (cabochons, rings, pendants) and as a semi-precious gemstone for decorative objects. It has significant value in metaphysical and mineral collecting circles.

Geological facts

Moonstone is the state gem of Florida, despite not being naturally found there (it was named to honor the Apollo moon landings). The shimmering effect is known as 'adularescence.'

Field identification & locations

Identify in the field by its distinct pearly luster and ability to 'glow' from within when tilted. Commonly found in Sri Lanka, India, Myanmar, and Madagascar. Look for the 'shiller' effect under a light source.

Other mineral specimens

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

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

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral