Clinotyrolite

Crystal System: Monoclinic
Status of Occurrence: Unconfirmed Occurrence
Distribution: Rare
Chemical Composition: Copper calcium arsenate sulphate hydroxide hydrate
Chemical Formula: Cu2+9Ca2[(As,S)O4]4(O,OH)10.10H2O
Method(s) of Verification: none.

Chemical Group:

  • Arsenates
  • Sulphates

Geological Context:

  • Supergene: in situ natural oxidation & weathering deposits
Introduction: clinotyrolite is a secondary mineral found typically in the oxidized zone of copper-bearing ore bodies.
Occurrence in Wales: the presence of this species is as yet unconfirmed. However, a number of tyrolite occurrences have produced XRD patterns that do not match ideal tyrolite (see for example Cotterell et al., 2011), while tyrolite from Gwaith-yr-Afon Mine was described by Rust & Mason (1994) as sulphatian. Further research is required to establish the true identity of all Welsh tyrolites.

Key Localities:

There are no key localities for this specimen.

References:

  1. Cotterell, T.F., Green, D.I., Hubbard, N., Mason, J.S., Starkey, R.E. and Tindle, A.G., 2011. The Mineralogy of Dolyhir Quarry, Old Radnor, Powys, Wales. UK Journal of Mines and Minerals, 32, 5-61.
  2. 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.