mineral

Chalcanthite

Copper(II) sulfate pentahydrate (CuSO4·5H2O)

AI-generated identification · may be incorrect

Hardness: 2.5 on Mohs scale. Color: Electric bright blue to deep blue. Luster: Vitreous (glassy). Crystal structure: Triclinic. Cleavage: Imperfect. Specific Gravity: ~2.2-2.3. Highly water-soluble.

Hardness: 2
Color: Electric bright blue to deep blue
Luster: Vitreous (glassy)

Identified July 25, 2026More mineral →

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Physical properties

Hardness: 2.5 on Mohs scale. Color: Electric bright blue to deep blue. Luster: Vitreous (glassy). Crystal structure: Triclinic. Cleavage: Imperfect. Specific Gravity: ~2.2-2.3. Highly water-soluble.

Formation & geological history

Forms in arid, dry environments as a secondary mineral in the oxidized zones of copper deposit deposits. It often forms as efflorescences or crusts on mine walls.

Uses & applications

Mainly collected by mineral enthusiasts due to its striking bright blue color. Historically used in copper mining as a minor ore and as a fungicide/herbicide, though synthetic versions are used today.

Geological facts

Natural chalcanthite is quite rare and delicate because it easily dissolves in water and can dehydrate (lose water molecules) in low humidity, turning into a white powder.

Field identification & locations

Can be identified by its distinctive bright turquoise-blue color, low hardness, and immediate solubility in water. Collectors must keep specimens dry and away from humidity.