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 with pearly luster; Crystal structure: Monoclinic; Cleavage: Perfect in two directions; Adularescence (schiller) effect.

Hardness
6-6
Color
Peach, salmon, or tan with pearly luster
Identified More mineral

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Physical properties

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

Formation & geological history

Formed in igneous and metamorphic environments, specifically within granitic pegmatites. The distinct sheen is caused by light scattering between alternating layers of orthoclase and albite during cooling.

Uses & applications

Primarily used in jewelry (cabochons, beads), decorative carvings, and as a popular specimen for crystal collectors and spiritual practitioners.

Geological facts

The 'moon-like' glow of this mineral is known as adularescence. It was named by the Roman historian Pliny, who believed its appearance shifted with the phases of the moon.

Field identification & locations

Identify by its unique silky, pearly luster and internal glow. Common sources include India, Sri Lanka, Madagascar, and parts of the USA. It is easily scratched by quartz, so handle with care.