Descloizite

Crystal System: Orthorhombic
Status of Occurrence: Confirmed Occurrence
Distribution: Rare
Chemical Composition: Lead zinc vanadate hydroxide
Chemical Formula: PbZn(VO4)(OH)
Method(s) of Verification: Esgair Hir Mine - XRD (Natural History Museum, XRD ref. 6669F).

Chemical Group:

  • Vanadates

Geological Context:

  • Supergene: post-mining oxidation & weathering deposits
  • Supergene: in situ natural oxidation & weathering deposits
Introduction: descloizite is a secondary mineral which occurs typically in the oxidized zones of base-metal ore deposits. Associated minerals may include vanadinite, mottramite and wulfenite plus a range of commoner Cu-Pb-Zn secondary minerals.
Occurrence in Wales: the only record of descloizite from Wales is that from Esgair Hir Mine (S.A. Rust Collection), where it occurs as part of a complex, fine-grained intergrowth, to the extent that it was only detected through X-ray diffraction analysis.

Key Localities:

  • Esgairhir Mine, Tal-y-bont, Ceredigion: detected by X-ray diffraction analysis as part of a complex intergrowth also including brochantite and linarite, apparently pseudomorphing an earlier lead-copper sulphate (S.A. Rust Collection; British Micromount Society Newsletter No. 21, 1987).

References:

There are no references for this specimen.