mineral

Covellite

Covellite (CuS)

Hardness: 1.5-2.0, Color: Indigo-blue to black with iridescent purple/gold, Luster: Submetallic to resinous, Crystal Structure: Hexagonal, Cleavage: Perfect basal (micaceous), SG: 4.6-4.7

Hardness: 1

Identified June 10, 2026More mineral →

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Physical properties

Hardness: 1.5-2.0, Color: Indigo-blue to black with iridescent purple/gold, Luster: Submetallic to resinous, Crystal Structure: Hexagonal, Cleavage: Perfect basal (micaceous), SG: 4.6-4.7

Formation & geological history

Formed as a secondary mineral in the oxidation zones of sulfide copper deposits, often found as coatings on other copper minerals like chalcocite or chalcopyrite. It is typically associated with hydrothermal veins.

Uses & applications

Used primarily as a minor ore of copper and as a decorative stone in wire-wrapped jewelry or as unique faceted gems for collectors. Highly valued by mineral collectors for its unique indigo color.

Geological facts

Covellite was the first discovered natural mineral that acts as a superconductor at low temperatures. It is named after the Italian mineralogist Niccolo Covelli who first discovered it near Mount Vesuvius.

Field identification & locations

Identify by its characteristic 'indigo' blue color and intense purple-to-copper flash when wet or tilted. Feel for its low hardness (can be scratched by a fingernail). Commonly found in Butte, Montana, and Italy.