mineral

Satin Spar (often sold as Selenite)

Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)

AI-generated identification · may be incorrect

Hardness: 2 on Mohs scale (can be scratched by a fingernail). Color: Pearly white, translucent. Luster: Silky or pearly. Crystal structure: Monoclinic, typically fibrous. Cleavage: Perfect in one direction.

Hardness: 2 on Mohs scale (can be scratched by a fingernail)
Color: Pearly white, translucent
Luster: Silky or pearly

Identified July 13, 2026More mineral →

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Physical properties

Formation & geological history

Formed as an evaporite mineral in sedimentary environments, often where seawater has evaporated or in clay beds and caves.

Uses & applications

Used primarily for ornamental purposes, carving, decorative lamps, and by collectors. Industrial gypsum is used in drywall and plaster.

Geological facts

While commonly called 'Selenite' in the metaphysical community, this fibrous variety is scientifically 'Satin Spar'. True Selenite is transparent and forms flat, window-like plates.

Field identification & locations

Identified by its intense silky luster and its softness; it is one of the few minerals easily scratched by a fingernail. Commonly found in Morocco, Mexico, and the USA.