mineral

Satin Spar Gypsum (Satin Spar Selenite tower)

Gypsum (CaSO4·2H2O)

Hardness: 2 on Mohs scale (scratchable by a fingernail). Color: White, translucent, silky appearance. Luster: Pearly to silky fibrous. Crystal structure: Monoclinic, forms fibrous parallel aggregate columns. Cleavage: Perfect in one direction.

Hardness: 2 on Mohs scale (scratchable by a fingernail)
Color: White, translucent, silky appearance
Luster: Pearly to silky fibrous

Identified July 24, 2026More mineral →

Explore Satin Spar Gypsum (Satin Spar Selenite tower) in the encyclopedia →

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Physical properties

Formation & geological history

Formed as an evaporite mineral in ancient marine basins and salt lakes through the concentration and evaporation of alkaline, calcium-, and sulfate-rich waters.

Uses & applications

Widely carved into decorative crystal towers, lamps, and palm stones for display and metaphysical collecting; commercial gypsum is used for drywall, plaster, and soil conditioning.

Geological facts

Trade names often call this 'Selenite', though geologically true selenite refers to clear, transparent gypsum sheets, while this fibrous, silky variety is properly termed satin spar. It is extremely soft and soluble in water over time.

Field identification & locations

Can be easily identified by its soft fibrous structure and extremely low Mohs hardness (can be scratched with a fingernail). Commonly produced in Morocco and found worldwide in evaporite deposits.

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Gypsum (variety Selenite or Alabaster)

Calcium sulfate dihydrate (CaSO4·2H2O)

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