Metastudtite
The lower-water polymorph of studtite — a uranium peroxide mineral formed by radiolysis of water.
Intro adapted from Wikipedia (CC BY-SA).
Metastudtite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula UO₄·2H₂O.
It crystallizes in the orthorhombic crystal system (space group Immm).
Key properties: specific gravity 4.67; Yellowish white streak; Silky luster; optically biaxial.
IMA symbol Mstu, IMA status: approved, named in 1981.
Extremely rare, on museum specimens of dolomite and uraninite, from the oxidized zone of a uranium deposit.
It is found associated with Uraninite, uranophane, soddyite, uranopilite, fourmarierite, wölsendorfite, rutherfordine, becquerelite, masuyite, kasolite.
As a dehydration product of studtite.