Dolfrwynog Mine

Overview

Copper and gold workings around Capel Hermon in Coed y Brenin, the most important copper producer of the Dolgellau district in the first half of the nineteenth century. Rich pockets of gold were found in the 1850s, and the adjoining Turf Copper Mine — unique in Britain — worked copper out of peat.

History

Dolfrwynog is a group of copper and gold workings about Capel Hermon, north of Dolgellau, in what is now the Coed y Brenin forest. Buddlepit records work at various times between 1851 and 1919, with 1,542 tons of copper concentrate between 1824 and 1847 the only recorded output, and notes that some gold was produced but that promotion overshadowed production. The Geological Conservation Review calls the group about Capel Hermon, known as the Dolfrwynog Mine, the most important copper producer in the district in the first half of the nineteenth century, with several rich pockets of gold found in the 1850s and mining finished by the end of the 1860s.

The veins strike north-east and carry massive quartz, pyrite and some chalcopyrite. Beside the vein workings lay the Turf Copper Mine, where copper-rich peat was stripped, burnt in a kiln and the ashes smelted — a practice unique in the British Isles, and the reason the ground is now protected for its copper-tolerant vegetation.

Geology

North-east striking veins with massive quartz, pyrite and some chalcopyrite. The workings lie in the Coed y Brenin porphyry copper system, where copper was also remobilised and reprecipitated into a peat bog in Holocene times — the deposit worked as the Turf Copper Mine.

Workings

Vein workings for copper and gold, with recorded output from 1824 to 1847 and work at various times from 1851; at the adjoining turf workings copper-bearing peat was stripped, burnt in a kiln and the ashes smelted.

Closure

The Geological Conservation Review says mining had ceased by the end of the 1860s; Buddlepit gives the working span as 1851 to 1919, which may cover later trials on parts of the sett.

What remains

A 2007 Geograph photograph shows the mine's site as a forest clearing with scant ruins among bracken and scrub in Coed y Brenin; the turf ground is a Site of Special Scientific Interest for its copper-tolerant vegetation.

Scant ruins in a forest clearing among bracken and scrub, photographed in 2007.

Redevelopment

The area is Forestry Commission plantation, Coed y Brenin, with the turf ground protected as an SSSI.

Related mines

• Turf Copper Mine — Dolfrwynog's vein workings adjoin the Turf copper bog and were partly driven in search of the peat copper's 'mother lode'.

Recorded claims

Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.

• The Geological Conservation Review describes the group of workings about Capel Hermon, known as the Dolfrwynog Mine, as the most important copper producer in the district in the first half of the nineteenth century. ¹
• Buddlepit records work at various times between 1851 and 1919, with 1,542 tons of copper concentrate between 1824 and 1847 the only recorded output, and says promotion activities overshadowed production. ²
• At the adjoining Turf Copper Mine copper-rich peat was stripped, burnt in a kiln and the ashes smelted — a site the GCR calls unique in the British Isles; the ground is now an SSSI for its copper-tolerant vegetation. ^1,3
• Several rich pockets of gold were found at the site in the 1850s, and mining had ceased by the end of the 1860s. ¹

Photographs & further reading

Sources

1. (secondary) Coed y Brenin Porphyry Copper System (Geological Conservation Review) — GeoGuide / GCR
2. (secondary) Dolfrwynog (Buddlepit mine database) — Buddlepit
3. (observational) Forest clearing with the ruins of a copper mine (Geograph photo 501807, 2007) — Geograph

Record created: 17 September 2026 · Last researched: 17 September 2026