Crystal System: Triclinic
Status of Occurrence: Confirmed Occurrence
Distribution: Rare
Chemical Composition: Lead copper sulphate hydroxide
Chemical Formula: Pb4Cu(SO4)2(OH)6
Method(s) of Verification: Llechweddhelyg Mine and Esgair Hir Mine: both confirmed by XRD at the Natural History Museum, London.

Chemical Group:

  • Sulphates

Geological Context:

  • Supergene: post-mining oxidation & weathering deposits
Pale blue chenite microcrystal from Esgair Hir Mine in the Central Wales Orefield. Specimen and photo S.A. Rust. © S.A. Rust.
Introduction: a secondary mineral typically formed in oxidized lead and copper-bearing ore bodies and within weathered slag derived from lead and copper smelting.
Occurrence in Wales: chenite is one of a number of rare lead-copper supergene species discovered in recent years within old mine dumps in Central Wales. Formed within the post-mining environment, it is to date only known from two localities and few specimens are known to exist.

Key Localities:

  • Esgairhir Mine, Tal-y-bont, Ceredigion: an extremely limited occurrence of chenite. It has been observed as equant sky blue crystals, up to 0.4 mm in size, occurring in association with susannite (Rust, 1997).
  • Llechweddhelyg Mine, Penrhyncoch, Ceredigion: this is the first Welsh occurrence of chenite. It was found within two small cavities in altered veinstone, containing groups of translucent sky blue sub-parallel slightly rounded platy crystals (up to 1.5 mm) (Rust, 1994).


  1. Rust, S., 1997. Chenite from Esgair Hir Mine, Talybont, Dyfed. UK Journal of Mines and Minerals, 18, 16.
  2. Rust, S.A., 1994. Chenite from Llechwedd Helyg Mine, Tir-y-Mynach, Dyfed, Wales. UK Journal of Mines and Minerals, 14, 9.