Mineral Database (Saesneg yn unig)

Mineral Database (Saesneg yn unig)
Mineralogy of Wales

Bindheimite

Crystal System: Cubic
Formula: Pb2Sb2O6(O,OH)
Status of Occurrence: Confirmed Occurrence
Distribution: Locally Abundant
Chemical Composition: Lead antimony oxide hydroxide
Method(s) of Verification: Bwlch Mine - IR (G. Ryback, unpublished data); Bwlchrhennaid Mine - XRD (NHM, 6335F); Frongoch Mine - XRD (NMH, x13502); Goginan Mine - XRD (NHM, 6718F); Logaulas Mine - XRD (NMW X-1321); Machen Quarry - XRD (NMW-853).
Chemical Group:
  • Oxides & Hydroxides
Geological Context:
  • Supergene : in situ natural oxidation & weathering deposits
Introduction: a secondary mineral, belonging to the stibiconite group, commonly found in the oxidized zone of antimony-bearing lead deposits.
Occurrence in Wales: bindheimite was first described from Wales by Russell (1944), who described brownish-yellow to honey-yellow alteration crusts on semseyite from Bwlch Mine near Deganwy in North Wales. Confirmation of this occurrence was later made by Ryback (unpublished infra-red data, quoted in Bevins, 1994). In Central Wales bindheimite is widespread, as an alteration product of decayed galena and ullmannite. Jones & Moreton (1977) described powdery yellow bindheimite in cavities in quartz from Frongoch and Eaglebrook mines. At Frongoch and Eaglebrook, the cavities are the result of total decay of antimony-bearing galena, probably in part, due to fine inclusions of ullmannite within the galena. Occasionally, pseudomorphs showing direct replacement of larger, discrete, cubic ullmannite crystals are recorded. Particulary, at Hendrefelen, Frongoch and Mynyddgorddu mines. In terms of abundance, the richest sites for bindheimite in Central Wales are Frongoch and Logaulas where, bright yellow, powdery masses liberally coat cerussite-lined cavities in intensely weathered galena-rich veinstone. Further south, bindheimite is recorded, again, in association with altered galena, from Machen (Plant & Jones, 1995) and Ochrwyth (Bevins & Mason, 2000) quarries in South Wales. At Machen bindheimite occurs as typical powdery, canary-yellow coatings on galena (Plant & Jones, 1995). Bindheimite is potentially more widespread. The inconspicuous nature of powdery coatings, likely results in many collectors ignoring its presence
Key Localities:
  • Bwlch Mine, Deganwy, Gwynedd: bindheimite is recorded replacing both semseyite (Russell, 1944) and stibnite (Ryback, unpublished data quoted in Bevins, 1994) from the shaft dumps. Russell (1944) describes brownish-yellow bindheimite, forming a crust on altered granular semseyite, and a resinous honey-yellow crystalline crust allied to or identical to bindheimite investing crystallized semseyite. Bevins (1994) records bindheimite as light brown crusts on stibnite and quartz.
  • Bwlchrhennaid Mine, Goginan, Ceredigion: resinous to powdery yellow masses are recorded by S. Rust (Cooper, 1987).
  • Eaglebrook (Nantycagl) Mine, Ceulanymaesmawr, Ceredigion: rare in comparison to some Central Wales sites. Jones & Moreton (1977) and Jones (1983) describe bindheimite from Eaglebrook as, typical yellow, powdery masses associated with fine-grained galena on the most westerly dumps.
  • East Penycefn Mine, Bont-goch, Ceredigion: an unusually rich occurrence. Bindheimite was formerly common, along with cerussite and pyromorphite prior to obliteration of the site (Bevins & Mason, 1997).
  • Frongoch Mine, Devil's Bridge, Ceredigion: Jones & Moreton (1977) describe yellow, powdery bindheimite in quartz cavities. Bindheimite is common at Frongoch, occurring abundantly on the extensive dumps, as pale yellow, powdery coatings within sugary quartz associated, with cerussite. Green et al. (1996) note that resinous cubic pseudomorphs after ullmannite, are frequently observed.
  • Gwaithgoch Mine, Pontrhydygroes, Ceredigion: bindheimite is abundant on surface dumps below the vein outcrop, forming yellow powdery patches replacing altered ullmannite.
  • Hendrefelin Mine, Ysbyty Ystwyth, Ceredigion: bindheimite occurs as pseudomorphs showing direct replacement of cubic ullmannite crystals (Clark & Rust, 1993).
  • Logaulas Mine, Ysbyty Ystwyth,Ceredigion: bindheimite is common, as rich, yellow, powdery masses associated with cerussite in opencast workings.
  • Machen Quarry, Caerphilly, South Wales: Bevins (1994) reported that yellow antimony-bearing coatings on galena were thought to be bindheimite. This has proved to be the case with, bindheimite now known to occur commonly, as powdery, canary-yellow coatings within cavities in galena (Plant & Jones, 1995). Cerussite and anglesite crystals developed within galena cavities are frequently encrusted with bindheimite.
  • Mynydd Gorddu Mine, Bontgoch, Ceredigion: Clark & Rust (1993) list bindheimite as one of the supergene species found at Mynyddgorddu. Bindheimite is known to replace ullmannite (Bevins & Mason, 1997).
References:
  • Bevins, R.E., 1994 A Mineralogy of Wales  National Museum of Wales, Geological Series No. 16, Cardiff, 146pp.
  • Bevins, R.E. & Mason, J.S., 1998 Welsh Metallophyte and metallogenic evaluation project: Results of a Minesite Survey of Gwynedd.  National Museums of Wales, Cardiff.
  • Bevins, R.E. & Mason, J.S., 1997 Welsh metallophyte and metallogenic evaluation project: Results of a minesite survey of Dyfed and Powys.  CCW Contract Science Report No. 156. National Museums & Galleries of Wales.
  • Bevins, R.E. & Mason, J.S., 2000 Welsh Metallophyte and metallogenic evaluation project: Results of a Minesite Survey of Glamorgan and Gwent.  National Museums & Galleries of Wales, Cardiff
  • Clark, A.M. & Rust, S.A., 1993 Bottinoite, a mineral new to Britain.  Mineralogical Magazine. 57, 543-544.
  • Cooper, M.P., 1987 New finds.  British Micromount Society Newsletter, 20, 6-9.
  • Green, D.I., Rust, S.A. & Mason, J.S., 1996 Classic British mineral localities: Frongoch Mine, Dyfed.  UK Journal of Mines & Minerals, 17, 29-38.
  • Jones, A.D., 1983 Nant-y-Cagl.  Mineral Realm, 3, 42-76.
  • Jones, J.A. & Moreton, N.J.M., 1977 The Mines and Minerals of Mid-Wales  40pp.
  • Plant, S.P. & Jones, I.E., 1995 Minerals of Machen Quarry, Mid Glamorgan, Wales.  Journal of the Russell Society, 6(1), 31-36.
  • Russell, A., 1944 Notes on some minerals either new or rare in Britain.  Mineralogical Magazine, 27, 1-10.