Metakahlerite
Metakahlerite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Fe²⁺(UO₂)₂(AsO₄)₂·8H₂O.
It crystallizes in the triclinic crystal system (space group P-1).
Key properties: specific gravity 3.73–3.77; Pearly on {001} luster; optically uniaxial.
IMA symbol Mkah, grandfathered status — known before the IMA’s founding, named in 1958.
Found as a secondary mineral in the oxidized zone of U–As bearing deposits.
It is found associated with Arseniosiderite, scorodite, löllingite, uraninite, siderite (Hüttenberg, Austria); kahlerite (Southwick Cliffs, Scotland).
The prefix meta- denotes the dehydration product of kahlerite.
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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