mineral

Satin Spar (often marketed as Selenite)

Gypsum (CaSO4·2H2O)

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

Identified June 5, 2026More mineral →

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Physical properties

Formation & geological history

Formed as an evaporite mineral in sedimentary environments, typically from the evaporation of ancient seawater or saline lakes. Most commercial specimens are from Morocco.

Uses & applications

Commonly used in the metaphysical and gemstone trade as decorative towers, wands, and bowls. Industrial gypsum is used for plaster, drywall, and fertilizer.

Geological facts

While commonly called 'Selenite' in the crystal trade, this fibrous variety is technically 'Satin Spar.' True Selenite is transparent and plate-like. It is extremely water-soluble and will dissolve if left in water for long periods.

Field identification & locations

Identify by its extreme softness and fibrous, silky appearance. It is very common in arid regions like Morocco, Mexico, and the USA (Utah/New Mexico). Collectors should avoid getting it wet.

Other mineral specimens

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

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metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Biotite Schist

Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]

metamorphic