mineral

Satin Spar Selenite

Calcium Sulfate Dihydrate (CaSO4·2H2O)

Hardness: 2 (can be scratched with a fingernail); Color: Translucent white; Luster: Pearly to silky; Crystal Structure: Monoclinic with fibrous habit; Cleavage: Perfect in one direction; Specific Gravity: 2.3

Hardness: 2 (can be scratched with a fingernail)
Color: Translucent white
Luster: Pearly to silky

Identified January 25, 2026More mineral →

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Physical properties

Formation & geological history

Formed as an evaporite mineral in sedimentary environments where seawater or saline groundwater evaporates. It can also form in hydrothermal veins or around volcanic fumaroles.

Uses & applications

Used extensively in the manufacture of drywall (plasterboard), cement, and plaster of Paris. It is also popular in the metaphysical community for crystal healing and as decorative carvings.

Geological facts

The name 'Selenite' comes from the Greek word 'selene' meaning moon, referring to its moon-like glow. The famous Naica Mine in Mexico contains giant selenite crystals over 30 feet long.

Field identification & locations

Identify in the field by its extreme softness and its characteristic silky, fibrous appearance that light reflects off of (chatoyancy). Commonly found in desert regions, dried lake beds, and near salt domes.

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