Crystal System: Monoclinic
Status of Occurrence: Confirmed Occurrence - 1st UK recording
Distribution: Rare
Chemical Composition: Hydrated iron sulphate
Chemical Formula: FeSO4.4H2O
Method(s) of Verification: Parys Mountain - XRD (D.A. Jenkins, University of Wales, Bangor).

Geological Context:

  • Supergene: post-mining oxidation & weathering deposits
Introduction: rozenite typically forms as a supergene product of pyrite decay and as such is often associated with a wide range of iron sulphates such as jarosite and melanterite.
Occurrence in Wales: the only known occurrence in the UK is as a post-mining mineral at Parys Mountain on Anglesey (Jenkins et al., 2000). White to yellowish post-mining sulphate efflorescences are, however, widespread in Wales, and it may be the case that there are other occurrences as these have in the main received little detailed study.

Key Localities:

  • Parys Mountain, Anglesey: noted, but without detailed description, as being part of the post-mining suite of supergene minerals at this site (Jenkins et al., 2000).


  1. Jenkins, D. A., Johnson, D. B. & Freeman, C., 2000. Mynydd Parys Cu-Pb-Zn mines: mineralogy, microbiology and acid mine drainage. pp. 161-179. In: Environmental Mineralogy: Microbial Interactions, Anthropogenic Influences, Contaminated Land and Waste Management (Cotter-Howells, J. D., Campbell, L. S., Valasami-Jones, E. & Batchelder, M., eds.). The Mineralogical Society of Great Britain & Ireland, London.