Metakirchheimerite
Metakirchheimerite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Co(UO₂)₂(AsO₄)₂·8H₂O.
It crystallizes in the triclinic crystal system (space group P-1).
Key properties: Mohs hardness 2–2.5; specific gravity 3.33; Pearly on {001} luster; optically uniaxial.
IMA symbol Mki, grandfathered status — known before the IMA’s founding, named in 1958.
A very rare secondary mineral formed in the oxidized zone of a U–As deposit.
It is found associated with Metakahlerite, nováčekite, metaheinrichite, erythrite, uraninite.
The prefix meta- denotes membership of this species in the meta-autunite group; the name honors Professor Franz Waldemar Kirchheimer (1911–).
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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