Kroupaite
Kroupaite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula KPb₀.₅[(UO₂)₈O₄(OH)₁₀]·10H₂O.
It crystallizes in the orthorhombic crystal system (space group Pbca). It is a member of the Schoepite structural group.
Key properties: Mohs hardness 2; specific gravity 5.058; Light yellow streak; Vitreous luster; optically biaxial.
IMA symbol Kpa, IMA status: approved, named in 2017.
Of supergene origin by oxidation-hydration alteration of uraninite.
It is found associated with Fourmarierite, Na-rich metaschoepite, uranopilite, liebigite, ewingite, gypsum.
The mineral was named to honor mining engineer Gustav Kroupa (1857-1935), who as head of the mining district.
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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