Dymkovite
Dymkovite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Ni(UO₂)₂(As³⁺O₃)₂·7H₂O.
It crystallizes in the monoclinic crystal system (space group C2/m). It is a member of the Seelite structural group.
Key properties: Mohs hardness 3; specific gravity 3.806; Pale yellow streak; Vitreous luster; optically biaxial.
IMA symbol Dym, IMA status: approved, named in 2010.
A secondary mineral found in small cavities and cracks in slightly oxidized uraninite-bearing dolomite veins.
It is found associated with Rauchite, uraninite, nickeline, gersdorffite, limonite, annabergite.
The mineral was named to honor Russian mineralogist, Yuriy Maksimovich Dymkov (b. 1926), a specialist in the mineralogy and geology of uranium deposits.