Crystal structure of Vandendriesscheite (water molecules omitted for clarity) — Photo: Klaproth · CC BY-SA 3.0
Vandendriesscheite
Vandendriesscheite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Pb₁.₆(UO₂)₁₀O₆(OH)₁₁·11H₂O.
It crystallizes in the orthorhombic crystal system (space group Pbca).
Key properties: specific gravity 5.45–5.46; optically biaxial.
IMA symbol Vdd, grandfathered status — known before the IMA’s founding, named in 1947.
Found in the oxidized zone of uranium-bearing mineral deposits.
It is found associated with Metavandendriesscheite, fourmarierite, becquerelite, metatorbernite, rutherfordine, uraninite (Shinkolobwe, Congo).
The mineral was named to honor Adrien Vandendriessche (1914–1940), Belgian mineralogist and geologist, University of Ghent, Ghent, Belgium.