Selenite (Satin Spar)
Gypsum (CaSO4·2H2O)
Rock Type: mineral

Physical Properties
Hardness: 2 (Mohs scale); Color: White to translucent; Luster: Pearly to silky; Crystal structure: Monoclinic; Cleavage: Perfect; Specific gravity: 2.3
Formation & Geological History
Formed in evaporite environments where sea or lake water rich in calcium and sulfate evaporates. Deposits can date from various geological periods, often associated with sedimentary basins.
Uses & Applications
Used in plaster of Paris, drywall, soil conditioners, and widely sold as decorative wands or towers for metaphysical purposes.
Geological Facts
Selenite is named after the Greek word for moon (Selene) due to its soft luminescence. It is so soft that it can be scratched with a fingernail.
Field Identification & Locations
Identified by its fiber-like structure (satin spar), extreme softness, and weight. Common locations include Morocco, Mexico, and the USA. Avoid water as it can dissolve over time.
Identified on: 4/28/2026
Mode: Standard