Mineral Database (Saesneg yn unig)
Hinsdalite
Crystal System: Hexagonal
Formula: PbAl3(SO4)(PO4)(OH)6
Status of Occurrence: Confirmed Occurrence
Distribution: Rare
Chemical Composition: Lead aluminium sulphate phosphate hydroxide
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
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).
References:
- 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.
