Comblainite
Comblainite is an IMA-recognized mineral species in the carbonate class, with the chemical formula Ni₄Co³⁺₂(CO₃)(OH)₁₂·3H₂O.
It crystallizes in the hexagonal crystal system. It is a member of the Hydrotalcite structural group.
Key properties: Mohs hardness 2; specific gravity 3.05; optically uniaxial.
IMA symbol Cob, IMA status: approved, named in 1978.
An alteration product of nickel and cobalt sulfides in the oxidized zone of a uranium deposit.
It is found associated with Uraninite, “metasaleeite”, uranophane, becquerelite, curite, rutherfordine, heterogenite.
The name refers to Gordon Comblain (1920–), Royal Museum of Central Africa, Tervuren, Belgium, who discovered the mineral.
Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet.
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