Chalcanthite
Image: Robert M. Lavinsky (CC BY-SA 3.0)
Mineral NameChalcanthite
Chemical FormulaCuSO₄·5H₂O
Mohs Hardness2.5
Crystal Systemtriclinic
Lustervitreous
Streak Colorwhite
Cleavageimperfect on {110} and {110}
Fractureconchoidal
Specific Gravity2.28
Colorsbright blue, sky-blue, greenish-blue
Transparencytransparent
Type LocalityBisbee, Warren District, Mule Mts, Cochise County, Arizona
Mineral GroupSulfates
Usescollector, minor source of copper (historically)
Associated Mineralsmalachite, azurite, brochantite, gypsum, limonite
Rarityuncommon
Description
This image displays a cluster of vibrant, deep blue chalcanthite crystals, exhibiting a vitreous luster and well-defined triclinic forms. The crystals appear to be prismatic or tabular, forming an attractive specimen.
Geological Context
Chalcanthite is a secondary mineral that forms in the oxidized zones of copper sulfide deposits, particularly in arid or semi-arid regions. It is highly soluble in water and often found as efflorescences or crusts in mine workings.
