Hinsdalite

Crystal System: Hexagonal
Status of Occurrence: Confirmed Occurrence
Distribution: Rare
Chemical Composition: Lead aluminium sulphate phosphate hydroxide
Chemical Formula: PbAl3(SO4)(PO4)(OH)6
Method(s) of Verification: Frongoch Mine - XRD, EDS and FTIR at the National Museum of Wales (XRD no. NMW X-1739).

Chemical Group:

  • Phosphates
  • Sulphates

Geological Context:

  • Supergene: in situ natural oxidation & weathering deposits
Scanning electron micrograph of spiky hinsdalite crystals (grey) encrusting pyromorphite (white) from Frongoch Mine. National Museum of Wales specimen, no. NMW 2007.18G.M.1a. © National Museum of Wales.
Scanning electron micrograph of an individual euhedral, rhombohedral, hinsdalite crystal from Frongoch Mine. Scale bar is 20 microns long. National Museum of Wales specimen, no. NMW 2007.18G.M.1a. © National Museum of Wales.
Introduction: a rare secondary mineral, typically of supergene origin, found in the oxidized zone of polymetallic sulphide deposits. Hinsdalite forms a solid solution series with corkite within the beudantite group. Visually hinsdalite is identical to plumbogummite, with which it is frequently confused.
Occurrence in Wales: Cotterell and Todhunter (2007) provided a detailed account of hinsdalite at Frongoch Mine, near Devil's Bridge in Ceredigion. Crystals from Frongoch are lead-rich, or plumbian hinsdalite, almost identical to the mineral orpheite, which in the view of Cotterell and Todhunter (2007) should be related to a variety of hinsdalite rather than a distinct species in its own right.

Key Localities:

  • Frongoch Mine, Devil's Bridge, Ceredigion: hinsdalite is uncommon, but occassionally occurs as thin crusts of spiky microcrystals coating coarsely crystallized pyromorphite on the extensive dumps. A full description is provided by Cotterell and Todhunter (2007).

There are no key localities for this specimen.

References:

  1. Cotterell, T.F. and Todhunter, P.K., 2007. Corkite and hinsdalite from Frongoch mine, Devil's Bridge, Ceredigion, Wales, including evidence to suggest that orpheite is a variety of hinsdalite. Journal of the Russell Society, 10, 57-64.

There are no references for this specimen.