mineral

Satin Spar (Satin Spar Selenite)

Gypsum (CaSO4·2H2O)

Hardness: 2 (Mohs scale); Color: White, Pearly; Luster: Silky/Satin-like; Crystal Structure: Monoclinic; Cleavage: Perfect; Specific Gravity: 2.3

Hardness: 2 (Mohs scale)
Color: White, Pearly
Luster: Silky/Satin-like

Identified June 12, 2026More mineral →

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Physical properties

Hardness: 2 (Mohs scale); Color: White, Pearly; Luster: Silky/Satin-like; Crystal Structure: Monoclinic; Cleavage: Perfect; Specific Gravity: 2.3

Formation & geological history

Formed as an evaporite mineral in sedimentary environments, specifically from the evaporation of saline waters in prehistoric sea beds or saline lakes.

Uses & applications

Used in plaster, drywall, fertilizer, and widely popular in the metaphysical community and lapidary arts for decorative carvings and lamps.

Geological facts

Satin spar is often confused with 'true' selenite, but it is identified by its fibrous structure that creates a cat's-eye effect (chatoyancy) when turned in the light.

Field identification & locations

Identify by its softness (it can be scratched with a fingernail) and silky fibrous appearance. Common in Morocco, Mexico, and the USA (Utah).

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