Bijvoetite-(Y)
Bijvoetite-(Y) is a very rare rare-earth and uranium mineral with the formula (Y,REE)8(UO2)16(CO3)16O8(OH)8·39H2O. When compared to the original description, the formula of bijvoetite-(Y) was changed in the course of crystal structure redefinition. Bijvoetite-(Y) is an example of natural salts containing both uranium and yttrium, the other examples being kamotoite-(Y) and sejkoraite-(Y). Bijvoetite-(Y) comes from Shinkolobwe deposit in Republic of Congo, which is famous for rare uranium minerals.
Intro adapted from Wikipedia (CC BY-SA).
Bijvoetite-(Y) is an IMA-recognized mineral species in the carbonate class, with the chemical formula Y₈(UO₂)₁₆O₈(CO₃)₁₆(OH)₈·39H₂O.
It crystallizes in the monoclinic crystal system (space group B2).
Key properties: Mohs hardness 2; specific gravity 3.907; Vitreous luster; optically biaxial.
IMA symbol Bij-Y, IMA status: approved, named in 1981.
Very rare, in the lower portion of the oxidation zone developed above uraninite-bearing dolomitic rocks.
It is found associated with Lepersonnite-(Gd), sklodowskite, curite, uranophane, becquerelite, rutherfordine, studtite, torbernite, soddyite, kasolite, schoepite, oursinite.
The mineral was named to honor Professor Johannes Martin Bijvoet (1892–1980), Dutch crystallographer.