mineral
Satin Spar (Gypsum)
Gypsum var. satin spar (CaSO4·2H2O)
AI-generated identification · may be incorrectMohs hardness of 2 (easily scratched by a fingernail), white to translucent color, distinct silky or pearly fibrous luster, and monoclinic crystal system.
Identified More mineral →
Explore Satin Spar (Gypsum) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Mohs hardness of 2 (easily scratched by a fingernail), white to translucent color, distinct silky or pearly fibrous luster, and monoclinic crystal system.
Formation & geological history
Forms primarily in sedimentary evaporite basins as saline water precipitates, or within fracture veins deposited by calcium sulfate-rich groundwaters.
Uses & applications
Commonly carved into decorative items, ornamental carvings, massage wands, and collected widely in mineral and crystal healing markets.
Geological facts
Commonly mislabeled commercially as true 'selenite' (transparent tabular gypsum); satin spar exhibits a chatoyant 'cat's eye' effect due to its parallel fibrous structure.
Field identification & locations
Identifiable by its extreme softness (scratched with a fingernail) and silky fibrous parallel grain; extensively mined in Morocco, Mexico, and the United States.
More like this
Other mineral specimens
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Tumbled granite
Granite, a coarse-grained felsic intrusive igneous rock
igneous
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Granite
Granite (Phaneritic intrusive igneous rock)
igneous