Krohnkite Location:  Chiquicamata, Chile. Scale: 3.5 x 2 cm. Copyright: © John Veevaert

Chemical Formula: Na2Cu(SO4)2·2H2O
Locality: Chuquicamata, Calama, Antofagásta Province, Chile.
Name Origin: Named after B. Kroehnke, who was the first person to analyze it.

Kröhnkite ( Na2Cu(SO4)2·2H2O ) is a rare copper sulfate mineral named after B. Kröhnke who first researched it.

Discovery and occurrence

Kröhnkite was first researched after an occurrence in the Chuquicamata Mine, Chile, and has been reported from a number of locations in the Atacama region. Associated minerals in the discovery location include; atacamite, blodite, chalcanthite, antlerite and natrochalcite. It occurs in the oxidized zone of copper deposits in arid environments.


Discovery date : 1876
Country of Origin: CHILE

Physical Properties

Cleavage: {010} Perfect, {011} Good
Color: Blue, Dark sky blue, Greenish blue, Yellowish green.
Density: 2.06 – 2.9, Average = 2.48
Diaphaneity: Transparent to Translucent
Fracture: Conchoidal – Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Hardness: 2.5-3 – Finger Nail-Calcite
Luster: Vitreous (Glassy)
Streak: white

Photos :

Krohnkite from Chuquicamata mine, El Loa Prov., Antofagasta, Chile © Dakota Matrix Minerals, Inc.
Mineral: Kröhnkite Locality: Chuquicamata, Antofagasta, Chile (Type Locality for Krohnkite) Overall Size: 15x6x6 cm Crystals: 1-12 cm © JohnBetts-FineMinerals
Chuquicamata Mine, Chuquicamata District, Calama, El Loa Province, Antofagasta Region, Chile © Rob Lavinsky, IRocks “”