mineral

Gypsum crystal cluster (selenite)

Gypsum, CaSO₄·2H₂O; likely a radiating selenite crystal formation

AI-generated identification · may be incorrect

Typically colorless to white with a vitreous to pearly luster; Mohs hardness 2, monoclinic crystal system, and perfect cleavage. The specimen shows large, pale, blade-like crystals clustered in radiating growths.

Identified October 13, 2026More mineral →

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Physical properties

Formation & geological history

Gypsum crystallizes when calcium- and sulfate-rich water evaporates or precipitates in caves and sedimentary basins. Such deposits form across many geological ages; the image alone cannot determine this specimen’s age or locality.

Uses & applications

Gypsum is widely used in plaster, drywall, and cement; clear selenite is collected and sometimes used decoratively. This large display specimen is primarily of museum or collector interest.

Geological facts

Gypsum is soft enough to be scratched with a fingernail, and its crystals can be cleaved into thin sheets. Selenite is a transparent-to-translucent variety of gypsum, not a separate mineral species.

Field identification & locations

Identify it by its very low hardness, pale color, and tabular or bladed crystals; common deposits occur in evaporite basins and caves worldwide. A precise locality would require a label or provenance, which is not visible here.