Mineralization at the Great Orme Copper Mines, Llandudno, North Wales

Rob Ixer
John Davies

Mineralization at the Great Orme Mines comprises rare galena-chalopyrite veins cutting fine-grained dolostones and extensive saddle dolomite-chalcopyrite-calcite ore infilling void spaces within coarse-grained limestones and dolomitized limestones close to small faults. Extensive supergene alteration of the primary copper ores has produced secondary copper sulphides and oxides together with multiple generations of calcite, limonite and malachite.

Mineral Notes

Monazite-(Ce) from Croft Gothal mine, Cornwall
John Betterton

Bismoclite a first Cornish occurrence at Croft Gothal mine
Steve Rust

Susannite and Caledonite in situ in Central Wales
Steve Rust

Tenorite from Penberthy Croft mine, Cornwall
John Betterton

Hildagoite and Arsenolite two new occurrences at Penberthy Croft mine, Cornwall
Steve Rust

Alpine-type Minerals from Bunmahon, Co. Waterford, Ireland
Beryl Taylor

Supergene copper mineralisation in situ at Lodge Park Copper Trial, Dyfed

John S. Mason
David I. Green

Post mining supergene copper mineralisation discovered in situ at Lodge Park trial in the Central Wales Orefield has yielded crystalline specimens of brochantite, connellite, copper, cuprite and langite, in a well-defined sequence of formation. The occurrence of connellite and euhedral cuprite crystals is unusual for Central Wales. The sequence of deposition and mineral associations can be interpreted in terms of a simple geochemical model.

Langite with minor alteration to brochantite, area of photo 12 x 8 mm. Richard Bell collection. Photo: David Green.

The minerals of Countybridge Quarry, Goonhilly Downs, The Lizard, Cornwall

Rev. Vincent Holyer

Countybridge Quarry on the Lizard peninsula has produced a suite of minerals including fine specimens of native copper, a number of secondary copper minerals, and colourful secondary serpentine

Copper in serpentine, (24 x 36 mm), Vincent Holyer collection. Photo: David Green.

Classic British Mineral Localities: Frongoch Mine, Dyfed

David I. Green
Steve A. Rust
John S. Mason

Frongoch was one of the largest and most important lead-zinc mines in Central Wales. The mining remains, although relatively recent, are of considerable archaeological significance, and the buildings are scheduled as an Ancient Monument. In mineralogical terms, Frongoch has long been known for excellent specimens of brown pyromorphite and cerussite. More recently, detailed study of the mineralogy of dump-altered sulphides has revealed an extensive suite of rare secondary species including bechererite, caledonite, elyite, lanarkite, namuwite, ramsbeckite, schulenbergite, susannite, and several as yet uncharacterised species. This is one of the most extensive suites of secondary minerals known at any mine in Wales, it includes the first British occurrence of bechererite, and the first Welsh occurrence of lanarkite

Transparent brown pyromorphite crystals 4 mm in length. Steve Rust collection. Photo: David Green.