mineral

Chalcanthite

Hydrated copper(II) sulfate (CuSO4·5H2O)

AI-generated identification · may be incorrect

Hardness: 2.5 (Mohs scale), Color: Sky blue to deep blue, Luster: Vitreous, Crystal structure: Triclinic, Cleavage: Imperfect, Specific Gravity: 2.2-2.3. It is highly soluble in water.

Hardness: 2

Identified July 17, 2026More mineral →

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Physical properties

Hardness: 2.5 (Mohs scale), Color: Sky blue to deep blue, Luster: Vitreous, Crystal structure: Triclinic, Cleavage: Imperfect, Specific Gravity: 2.2-2.3. It is highly soluble in water.

Formation & geological history

Formed in the oxidation zones of copper deposits, typically in arid climates. Often found as a secondary mineral as encrustations on mine walls (stalactites) or as a byproduct of copper leaching.

Uses & applications

Primarily used as a minor ore of copper, in copper plating, as an herbicide/fungicide in agriculture, and as a popular specimen for mineral collectors due to its vibrant color.

Geological facts

Naturally occurring crystals are rare and fragile; many specimens sold in shops are actually lab-grown from copper sulfate solution. It is highly water-soluble and will dissolve if exposed to high humidity or washed.

Field identification & locations

Identify by its intense electric blue color and tendency to dissolve in water (producing a metallic taste - though caution is advised as it is toxic if ingested). Commonly found in arid copper-mining regions like Chile and Arizona.