Belakovskiite
A very rare uranyl sulfate containing a hydrosulfate group — a feature it shares only with meisserite.
Intro adapted from Wikipedia (CC BY-SA).
Belakovskiite is an IMA-recognized mineral species in the sulfate class, with the chemical formula Na₇(UO₂)(SO₄)₄(SO₃OH)(H₂O)₃.
It crystallizes in the triclinic crystal system (space group P-1).
Key properties: Mohs hardness 2; specific gravity 2.953; White streak; Vitreous luster; optically biaxial.
IMA symbol Bkk, IMA status: approved, named in 2013.
A secondary efflorescence on sandstone in the oxidation zone of a Colorado Plateau type uraninite deposit.
It is found associated with Blödite, ferrinatrite, kröhnkite, meisserite, metavoltine.
The mineral was named to honor Dmitry Ilych Belakovskiy (b. 1957), a prominent Russian mineralogist and Curator of the A.E. Fersman Mineralogical Museum, Moscow, Russia.