Metauroxite
Metauroxite is an IMA-recognized mineral species in the organic mineral class, with the chemical formula (UO₂)₂(C₂O₄)(OH)₂(H₂O)₂.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Oxalate structural group.
Key properties: Mohs hardness 2; specific gravity 4.403; Very pale yellow streak; Vitreous luster.
IMA symbol Murx, IMA status: approved, named in 2019.
A post-mining secondary phase found in efflorescent crusts on mine walls on asphaltum-quartz matrix in bedded or roll-front U-V deposits in sandstone. Oxalate, C2O4 2-.
It is found associated with Uroxite, abernathyite, gypsum, tyuyamunite, uranopilite.
The prefix meta- denotes the compositional similarity to uroxite, with one less H2O group per formula unit. Uroxite identifies a uranyl (UR) oxalate (OX).