mineral

Moonstone (Green Moonstone / Garnierite)

Potassium Aluminum Silicate (KAlSi3O8) with inclusions of Garnierite

AI-generated identification · may be incorrect

Hardness: 6.0-6.5 on Mohs scale; Color: Pale green to silvery grey; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Perfect in two directions at 90 degrees; Specific Gravity: 2.56-2.59.

Hardness: 6
Color: Pale green to silvery grey
Luster: Vitreous to pearly

Identified April 26, 2026More mineral →

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Physical properties

Formation & geological history

Formed in igneous and metamorphic environments, specifically in pegmatites and deep-seated veins. Moonstone is a member of the feldspar group, specifically orthoclase, characterized by an optical phenomenon called adularescence.

Uses & applications

Primarily used in jewelry (cabochons, rings, pendants), crystal healing practices, and as a collector's specimen.

Geological facts

Green moonstone is sometimes called 'Garnierite' due to the nickel-rich green inclusions that provide the color. In folklore, moonstones are associated with new beginnings and lunar energy.

Field identification & locations

Identify by its 'silky' glow (adularescence) that moves across the surface as the stone is turned. It is commonly found in Sri Lanka, India, Madagascar, and Brazil. Collectors look for high clarity and a strong, unblemished glow.