mineral

Satin Spar (Selenite variant)

Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)

Hardness: 2 on Mohs scale (can be scratched by a fingernail). Color: White or pearly. Luster: Silky to pearly. Crystal structure: Monoclinic, typically fibrous. Cleavage: Perfect in one direction. Specific gravity: 2.3.

Hardness: 2 on Mohs scale (can be scratched by a fingernail)
Color: White or pearly
Luster: Silky to pearly

Identified April 7, 2026More mineral →

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Physical properties

Formation & geological history

Formed as an evaporite mineral in sedimentary environments, typically from the evaporation of seawater in prehistoric basins.

Uses & applications

Used in the manufacture of drywall (plasterboard), cement, and plaster of Paris. In this polished form, it is used for decorative objects, meditation stones, and metaphysical jewelry.

Geological facts

Satin spar is often confused with true Selenite (which is transparent) and Desert Rose. It is extremely water-soluble; soaking it in water can cause it to dissolve or lose its luster over time.

Field identification & locations

Identify by its extreme softness (scratches with a fingernail) and fibrous optical chatoyancy (cat's eye effect). Found commonly in Morocco, Mexico, and the USA (Utah). Do not use water to clean it.

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