Halite (Rock Salt)

Physical Properties

Hardness: 2.0-2.5 on Mohs scale; Color: Colorless to white (can be blue or pink with impurities); Luster: Vitreous; Crystal structure: Cubic; Cleavage: Perfect cubic; Specific gravity: 2.17

Formation & Geological History

Formed through the evaporation of seawater or saline lake water in sedimentary basins. These evaporite deposits can date from the Cambrian to modern times.

Uses & Applications

Used primarily as road salt for de-icing, in food preservation and seasoning, chemical manufacturing of chlorine and sodium hydroxide, and for livestock salt licks.

Geological Facts

Halite is unique because it is one of the few minerals that is edible and essential for human life. In ancient times, it was used as currency (where the word 'salary' originates).

Field Identification & Locations

Identify in the field by its distinct cubic cleavage, salty taste (not recommended for unknown samples), and solubility in water. Common in play deposits, salt domes, and dried lake beds like the Bonneville Salt Flats.

Identified on: 5/2/2026

Mode: Standard