Formula: Co(UO2)2(SO4)O2.3.5H2O
Hydrated sulphate, zippeite group, uranyl mineral
Crystal System: Monoclinic
Specific gravity: 4.948 calculated
Hardness: 2
Colour: Tan to brownish yellow, yellow-orange
Very strongly RADIOACTIVE Environments

Sedimentary environments
hydrothermal environments


At the type locality, the Happy Jack Mine, White Canyon Mining District, San Juan County, Utah, USA, cobaltzippeite occurs rarely as efflorescences on the mine walls in oxidised portions of the uraninite deposit containing gersdorffite. Associated minerals include natrozippeite, uranopilite, johannite, zeunerite, chalcanthite, antlerite, siderotil, bieberite, erythrite, epsomite and gypsum (HOM).

Cobaltzippeite from the Happy Jack Mine - Image

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