Gemstone profile and identification guide
Selenite
Selenite is a transparent crystalline gypsum variety used in decorative and collector contexts.
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Overview
Selenite is a transparent crystalline gypsum variety used in decorative and collector contexts.
Did you know? Selenite can be scratched by a fingernail due to its very low hardness.
Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.
Identification
Name: Selenite
Scientific classification: Sulfate (Gypsum Variety: Selenite)
Hardness: 2 Mohs
Transparency: translucent
Lustre: vitreous to silky
Crystal system: Monoclinic
Primary colour: Colorless
Secondary colour: White
Colour family: Whites & Neutrals
Very low hardness and perfect cleavage are key diagnostics.
Verification Status
Status: verified-core-fields
Reference priority: GIA, Gem-A, Mindat, International Gem Society
Core identity, locality, and physical-property fields reviewed against standard gemological references.
Trade-name and treatment-sensitive entries include explicit disclosure notes where applicable.
Physical Properties
Hardness category: soft
Hardness value: 2 Mohs
Chemical composition: Calcium sulfate dihydrate (CaSO4.2H2O)
Crystal system: Monoclinic
Common locations: Mexico, Morocco, Spain, United States
Learn more: Gem-A gemstone education resources.
Colour Variations
Transparent to translucent gypsum variety with soft silky to vitreous appearance.
Optical effects: Chatoyant Sheen (some cuts)
Detailed Gemology
Mineral species: Gypsum (selenite variety)
Mineral group: Sulfate group
Chemical formula: Calcium sulfate dihydrate (CaSO4.2H2O)
Mohs hardness: 2
Crystal system: Monoclinic
Lustre: vitreous to silky
Transparency: translucent
Streak: White
Cleavage: Perfect in one direction
Fracture: Fibrous to uneven
Specific gravity: 2.30-2.33
Refractive index: 1.52-1.53
Optical phenomena: Silky sheen in fibrous cuts
Colour range: Colorless to white
Common inclusions: Cleavage planes, fibrous growth lines
Geological environment: Evaporite sedimentary basins
Principal mining regions: Mexico, Morocco, Spain, United States
Important commercial sources: Selenite is sourced from evaporite and sedimentary deposits in multiple countries
Historical significance: Long-used ornamental and architectural soft mineral.
Common treatments: Generally untreated.
Synthetic or imitation forms: Glass and plastic imitations exist.
Common look-alikes: Calcite, satin spar gypsum
Jewellery uses: Used in carvings, decorative pieces, and collector crystals.
Care recommendations: Very soft and water-sensitive; avoid moisture, abrasion, and pressure.
Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Selenite.
Formation
Forms in evaporitic sedimentary environments and low-temperature aqueous systems.
Origin
Selenite is sourced from evaporite and sedimentary deposits in multiple countries
Uses
Best for: Used in carvings, decorative pieces, and collector crystals.
Ideal uses: Display objects rather than wearable jewelry.
Care
Very soft and water-sensitive; avoid moisture, abrasion, and pressure.
Need another candidate? Use advanced gemstone search or return to the identification guide.
Related gemstones by colour
Related gemstones by hardness
Commonly confused gemstones
Selenite FAQ
How can I identify Selenite?
Compare hardness (2 Mohs), crystal system (Monoclinic), colour profile, and lustre (vitreous to silky) with your sample. Then cross-check related gemstones listed above.
What colour range does Selenite appear in?
Transparent to translucent gypsum variety with soft silky to vitreous appearance.
Where is Selenite commonly used?
Display objects rather than wearable jewelry.. For maintenance, follow the care guidance in this profile.
Scientific References
GIA: general gemstone identity (reviewed) - Batch 08 factual verification pass.
Gem-A: gemological terminology and testing references (reviewed) - Batch 08 factual verification pass.
Mindat: mineral species and principal localities (reviewed) - Batch 08 factual verification pass.
International Gem Society: gem trade context and treatment overview (reviewed) - Batch 08 factual verification pass.