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Bryn-yr-Afr Mine, Nant-y-Moch Reservoir area, Ponterwyd, Trefeirig, Ceredigion (Dyfed; Cardiganshire), Wales, UK

Photo: Steve Rust
UK Grid Reference: SN745878
Latitude: 52°28'23"N
Longitude: 3°50'52"W
Refs: The Old Metal Mines of Mid-Wales Part 3. British Mining No 12, Northern Mines Research Society. UKJMM No17.

The mine is recorded as working from 1879 to 1912 quite late in the history of this 'ore field'. It is belived to have developed a section of the major Hafan Fault/vein system, to a depth of 77 fathoms. With a production of approx 4950 tons of lead ore, and 8115 tons of zinc ore. 4000 tonnes of "marcasite" was produced for the manufacture of sulphur.
Of special interest is the relatively large amount of millerite in the ore (which was not reclaimed) in comparison with other mines in the area. Some ore specimens collected from the dumps recently (2001) show masses of acicular crystals of millerite to 5cms long, embedded in massive sphalerite. Also the occurrence of alpine type cleft minerals, which line small rents to 1cm + in the mudstone/quartz veinstuff. This has lead to other mines in the mid-wales "orefield" also being found with this very early stage mineralisation. Which predates the main sulphide mineralisation period, but is part of the main vein/fault mineralisation in mid-Wales.

Mineral List

Albite
'Apatite'
Brochantite
Caledonite
Cerussite
Chalcopyrite
Dolomite
Galena
Goethite
Hemimorphite
Jamborite
Linarite
Marcasite
Millerite
Muscovite
Pyrite
Pyromorphite
Quartz
Rutile
Smithsonite
Sphalerite


21 entries listed. 20 valid minerals.

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Copyright © Jolyon Ralph and Ida Chau 1993-2011. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them.Further information contact the Site hosted & developed by Jolyon Ralph. Mindat.org is an online information resource dedicated to providing free mineralogical information to all. Mindat relies on the contributions of hundreds of members and supporters. Mindat does not offer minerals for sale. If you would like to add information to improve the quality of our database, then click here to register. Current server date and time: 3rd Jul 2011 11:53:40
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