Goslarite

Crystal System: Orthorhombic
Status of Occurrence: Confirmed Occurrence
Distribution: Rare
Chemical Composition: Zinc sulphate hydrate
Chemical Formula: ZnSO4.7H2O
Method(s) of Verification: method of verification is unknown, but numerous early references suggest that sufficient confirmation had been made

Chemical Group:

  • Sulphates

Geological Context:

  • Supergene: post-mining oxidation & weathering deposits
Sulphate of zinc (goslarite) found at Holywell in Flintshire, reproduced from Sowerby (1811).
Introduction: goslarite is a secondary mineral that typically forms efflorescent crusts as a result of the oxidation of sphalerite in old mine workings.
Occurrence in Wales: Sowerby (1811) described and illustrated sulphate of zinc found at Holywell in Flintshire. Phillips (1823) noted sulphate of zinc or white vitriol at the same locality while Greg & Lettsom (1858) directly refer to goslarite at Holywell. Although no analyses are known the inclusion within these high profile texts would suggest that this identification is reliable.

Key Localities:

  • Holywell, Flintshire: white coatings on red earthy oxide of iron. Sowerby (1811) notes that it has not been observed crystallized.

References:

  1. Greg, R.P. & Lettsom, W.G., 1858. Manual of the Mineralogy of Great Britain and Ireland. John van Voorst, London, 483pp.
  2. Phillips, W., 1823. An elementary introduction to the knowledge of Mineralogy. 3rd edition. London. 406pp.
  3. Sowerby, J., 1811. British Mineralogy. Volume IV, Richard Taylor, London.