mineral
Satin Spar (Satin Spar Gypsum)
Gypsum (CaSO4·2H2O)
Mohs hardness of 2 (can be scratched with a fingernail), fibrous crystal structure with a silky or pearly luster, translucent to white color, perfect cleavage in one direction.
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Physical properties
Mohs hardness of 2 (can be scratched with a fingernail), fibrous crystal structure with a silky or pearly luster, translucent to white color, perfect cleavage in one direction.
Formation & geological history
Formed as an evaporite mineral in saline lakes, playas, and shallow seas where seawater rich in calcium and sulfate evaporated.
Uses & applications
Popular in metaphysics and crystal healing as a cleansing stone, used for decorative carvings, lamps, polished sticks/wands, and in construction as plaster of Paris or drywall.
Geological facts
Satin spar is often commercially labeled and sold as 'Selenite', although true selenite forms clear, flat, sheet-like crystals, while satin spar consists of parallel fibrous aggregates that produce a cat's-eye (chatoyant) effect.
Field identification & locations
Identified by its extreme softness (easily scratched by a fingernail), silky sheen, and fibrous parallel structure. Commonly found in Morocco, Mexico, USA, and Poland.
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sedimentary
Schist
Schist
Metamorphic
Sandstone with Mineral Veining or Crust
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sedimentary
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
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Mineral/Rock