Rock Identifier
Peach Moonstone (Potassium Aluminum Silicate, KAlSi3O8) — mineral
mineral

Peach Moonstone

Potassium Aluminum Silicate, KAlSi3O8

Hardness: 6-6.5 Mohs scale; Color: Peach, salmon, or tan; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Perfect in two directions; Adularescence (schiller effect).

Hardness
6-6
Color
Peach, salmon, or tan
Luster
Vitreous to pearly
Identified More mineral

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Physical properties

Hardness: 6-6.5 Mohs scale; Color: Peach, salmon, or tan; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Perfect in two directions; Adularescence (schiller effect).

Formation & geological history

Formed in igneous and metamorphic rocks through the cooling of magma. The characteristic sheen results from thin layers of orthoclase and albite that create light diffraction.

Uses & applications

Predominantly used in jewelry (cabochons, beads, carvings), decorative ornaments, and by collectors for its unique optical properties.

Geological facts

Moonstone is a variety of the feldspar group mineral orthoclase. It has been used in jewelry for centuries, notably by the Romans who believed it was formed from frozen beams of moonlight.

Field identification & locations

Identify by its soft peach hue and the internal 'glow' or shimmer (adularescence) when rotated under light. Commonly found in Madagascar, Sri Lanka, and India. Collectors look for stones with a strong internal sheen and minimal cracks.