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Cymraeg

Wroewolfeite

Crystal System: Monoclinic
Status of Occurrence: Confirmed Occurrence
Distribution: Uncommon
Chemical Composition: Copper sulphate hydroxide hydrate
Chemical Formula: Cu4(SO4)(OH)6.2H2O
Method(s) of Verification: Darren Mine - XRD (NHM); Drws-y-Coed Mine - IR, (Braithwaite, 1982); Dylife Mine - visual; Eaglebrook Mine - Infrared spectroscopy (Braithwaite, 1982); Esgair Hir Mine - XRD (NHM); Frongoch Mine - XRD (NHM); Glasdir Mine - IR; Llechweddhelyg Mine - visual

Geological Context:

Bladed wroewolfeite crystals up to 1 mm long, from Eaglebrook Mine. Specimen National Museum of Wales (NMW 87.43G.M.36), ex A. Dean Collection, © National Museum of Wales.
Introduction: wroewolfeite is a late stage supergene copper mineral typically formed as microcrystals in the oxidized zone of copper-bearing ore deposits and in post-mining dump environments.
Occurrence in Wales: described as a new species by Dunn & Rouse (1975) from the Loudville lead mine, Massachusetts, U.S.A., wroewolfeite was already known on specimens from Eaglebrook (Nantycagal) Mine in Cardiganshire (now Ceredigion). In 1965 R.S.W. Braithwaite collected some of the finest examples of the species from the dumps at Eaglebrook Mine, including well-formed bladed crystals up to 1 mm in length. Further investigations revealed wroewolfeite at Drws-y-Coed Mine, in North Wales and then during the 1980s and 1990s a small number of new occurrences at minesites in Central Wales came to light with the increasing popularity of micromineral collecting.

Key Localities:

References:

  1. Bevins, R.E., 1994. A Mineralogy of Wales National Museum of Wales, Geological Series No. 16, Cardiff, 146pp.
  2. 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.
  3. Braithwaite, R.S.W., 1982a. Wroewolfeite in Britain. Mineralogical Record, 13, 167-174.
  4. Dunn, P.J. & Rouse, R.C., 1975. Wroewolfeite, a new copper sulphate hydroxide hydrate. Mineralogical Magazine, 40, 1-5.
  5. 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.
  6. Jones, A.D., 1983. Nant-y-Cagl. Mineral Realm, 3, 42-76.
  7. Rust, S. & Rust, D., 1987. Micro-minerals from Dyfngwm Mine. U.K. Journal of Mines and Minerals, No. 2, 28-32.
  8. Rust, S.A. & Mason, J.S., 1994. An unusual occurrence of arsenate minerals at Gwaith-yr-Afon mine, Dyfed, Wales. Journal of the Russell Society, 5(2), 109-113.
  9. Rust, S.A. & Mason, J.S., 1988. The minerals of Esgair-Hir mine, Dyfed, Wales. UK Journal of Mines & Minerals, 5, 35-43.