mineral

Satin Spar Selenite

Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)

Hardness: 2 (Mohs scale), Color: White to pearly translucent, Luster: Silky or pearly, Crystal Structure: Monoclinic, Cleavage: Perfect in one direction, Specific Gravity: 2.3

Identified June 12, 2026More mineral →

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Physical properties

Hardness: 2 (Mohs scale), Color: White to pearly translucent, Luster: Silky or pearly, Crystal Structure: Monoclinic, Cleavage: Perfect in one direction, Specific Gravity: 2.3

Formation & geological history

Formed as an evaporite mineral in sedimentary environments, specifically from the evaporation of saline waters in ancient lake beds or marine basins. Often found in deposits dating from the Permian or Triassic periods.

Uses & applications

Commonly used in plaster of Paris, wallboard (drywall), and as a soil conditioner. In its fiberous 'Satin Spar' form, it is highly popular for decorative carvings, metaphysical stones, and inexpensive jewelry.

Geological facts

The name 'Selenite' comes from the Greek word 'selene' meaning moon, due to its soft moon-like glow. It is chemically identical to Alabaster and Desert Rose but differs in crystal habit.

Field identification & locations

Identify by its extreme softness (can be scratched by a fingernail) and its distinctive fibrous, silky luster. Commonly found in Morocco, Mexico, and the USA (Utah/New Mexico). Collectors should avoid water as it can dissolve or dull the surface over time.

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Nephrite Jade

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Mineral/Rock

Banded Gneiss (River Rock/Pebble)

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Metamorphic Rock

Biotite Schist

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

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