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Gwynfynydd Mine, Ganllwyd, Gwynedd, Wales, UKi
Regional Level Types
Gwynfynydd MineMine (Abandoned)
GanllwydCommunity
GwyneddCounty
WalesCountry
UKCountry

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Latitude & Longitude (WGS84):
52° 50' 13'' North , 3° 52' 30'' West
Latitude & Longitude (decimal):
UK National Grid Reference:
SH737283
Type:
Mine (Abandoned) - last checked 2020
Kรถppen climate type:
Nearest Settlements:
PlacePopulationDistance
Trawsfynydd628 (2017)7.9km
Dolgellau2,688 (2017)10.6km
Llan Ffestiniog864 (2017)13.9km
Dyffryn Ardudwy1,654 (2012)14.3km
Llanbedr385 (2017)15.3km
Mindat Locality ID:
4280
Long-form identifier:
mindat:1:2:4280:5
GUID (UUID V4):
0
Other/historical names associated with this locality:
Gwynfynydd Gold Mine; Merionethshire; Gwyn Mine; Morgan Mine; Mount Morgan Mine; British Gold Fields


Second to Clogau in terms of gold output, Gwynfynedd ranked with Clogau and Glasdir, the latter primarily a copper mine, as one of the largest and richest mines in the Dolgellau gold belt.

The remains of the Gwynfynedd mill are at OS grid ref. SH 735274.

The earthwork remains of the gold mine at Gwynfynydd include shafts, levels, open cuts and stopes. There are also remains of the associated transport network including tramways and inclines. Surviving buildings include the winding houses and other associated buildings and structures.

Up to 20 parallel lodes in five main groups have been recognised: the Chidlaw, Collett, James, Harvey and Big lodes. The greatest thickness attained in a single vein being 20 feet in the Chidlaw lode. All strike nearly east-west and have been traced for up to a mile and a half.

Although the Gwyn tribute lease appears in the mineral statistics for 1911-12, it was characterised by low employment and low yields from a substantial tonnage of ore; it has been suggested that this was the bulk of the output of Prince Edward Mine after selected ore had been processed at Prince Edward.

Total returned production between 1862 and 1916 was 98,842 tons of gold ore yielding 40,054 ounces of gold (about half of that produced by Clogau). After the main phase of mining ended, the mine operated intermittently and on a much smaller scale until almost the present day. In recent times both the Clogau and Gwynfynydd mines have been exploited by companies taking advantage of the high premium payable for Welsh gold in the jewelry market.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.


Mineral List


15 valid minerals.

Detailed Mineral List:

โ“˜ Acanthite ?
Formula: Ag2S
Description: The National Museum of Wales database "The Minerology of Wales" (http://www.nmgw.ac.uk/en/791/)has raised doubts regarding the identifications of acanthite and sylvanite at this location.
โ“˜ Calcite
Formula: CaCO3
โ“˜ Chalcopyrite
Formula: CuFeS2
โ“˜ Galena
Formula: PbS
โ“˜ Goethite
Formula: Fe3+O(OH)
โ“˜ Halotrichite
Formula: FeAl2(SO4)4 · 22H2O
โ“˜ Marcasite
Formula: FeS2
โ“˜ Native Gold
Formula: Au
โ“˜ Native Gold var. Electrum
Formula: (Au,Ag)
โ“˜ Pickeringite
Formula: MgAl2(SO4)4 · 22H2O
โ“˜ Pyrite
Formula: FeS2
โ“˜ Pyrrhotite
Formula: Fe1-xS
โ“˜ Quartz
Formula: SiO2
References:
Dr. Gรผnter Grundmann collectionIdentified by Dr. Günter Grundmann: Polarised-light microscopy
โ“˜ Sphalerite
Formula: ZnS
โ“˜ Sylvanite ?
Formula: AgAuTe4
Description: The National Museum of Wales database "The Minerology of Wales" (http://www.nmgw.ac.uk/en/791/)has raised doubts regarding the identifications of acanthite and sylvanite at this location.
โ“˜ Tellurobismuthite
Formula: Bi2Te3
References:
Dr. Gรผnter Grundmann collectionIdentified by Dr. Günter Grundmann: Polarised-light microscopy

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
โ“˜Native Gold
var. Electrum
1.AA.05(Au,Ag)
โ“˜1.AA.05Au
Group 2 - Sulphides and Sulfosalts
โ“˜Acanthite ?2.BA.35Ag2S
โ“˜Sphalerite2.CB.05aZnS
โ“˜Chalcopyrite2.CB.10aCuFeS2
โ“˜Pyrrhotite2.CC.10Fe1-xS
โ“˜Galena2.CD.10PbS
โ“˜Tellurobismuthite2.DC.05Bi2Te3
โ“˜Sylvanite ?2.EA.05AgAuTe4
โ“˜Pyrite2.EB.05aFeS2
โ“˜Marcasite2.EB.10aFeS2
Group 4 - Oxides and Hydroxides
โ“˜Goethite4.00.Fe3+O(OH)
โ“˜Quartz4.DA.05SiO2
Group 5 - Nitrates and Carbonates
โ“˜Calcite5.AB.05CaCO3
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
โ“˜Halotrichite7.CB.85FeAl2(SO4)4 ยท 22H2O
โ“˜Pickeringite7.CB.85MgAl2(SO4)4 ยท 22H2O

List of minerals for each chemical element

HHydrogen
Hโ“˜ GoethiteFe3+O(OH)
Hโ“˜ HalotrichiteFeAl2(SO4)4 · 22H2O
Hโ“˜ PickeringiteMgAl2(SO4)4 · 22H2O
CCarbon
Cโ“˜ CalciteCaCO3
OOxygen
Oโ“˜ CalciteCaCO3
Oโ“˜ GoethiteFe3+O(OH)
Oโ“˜ HalotrichiteFeAl2(SO4)4 · 22H2O
Oโ“˜ PickeringiteMgAl2(SO4)4 · 22H2O
Oโ“˜ QuartzSiO2
MgMagnesium
Mgโ“˜ PickeringiteMgAl2(SO4)4 · 22H2O
AlAluminium
Alโ“˜ HalotrichiteFeAl2(SO4)4 · 22H2O
Alโ“˜ PickeringiteMgAl2(SO4)4 · 22H2O
SiSilicon
Siโ“˜ QuartzSiO2
SSulfur
Sโ“˜ AcanthiteAg2S
Sโ“˜ ChalcopyriteCuFeS2
Sโ“˜ GalenaPbS
Sโ“˜ HalotrichiteFeAl2(SO4)4 · 22H2O
Sโ“˜ MarcasiteFeS2
Sโ“˜ PickeringiteMgAl2(SO4)4 · 22H2O
Sโ“˜ PyriteFeS2
Sโ“˜ PyrrhotiteFe1-xS
Sโ“˜ SphaleriteZnS
CaCalcium
Caโ“˜ CalciteCaCO3
FeIron
Feโ“˜ ChalcopyriteCuFeS2
Feโ“˜ GoethiteFe3+O(OH)
Feโ“˜ HalotrichiteFeAl2(SO4)4 · 22H2O
Feโ“˜ MarcasiteFeS2
Feโ“˜ PyriteFeS2
Feโ“˜ PyrrhotiteFe1-xS
CuCopper
Cuโ“˜ ChalcopyriteCuFeS2
ZnZinc
Znโ“˜ SphaleriteZnS
AgSilver
Agโ“˜ AcanthiteAg2S
Agโ“˜ Native Gold var. Electrum(Au,Ag)
Agโ“˜ SylvaniteAgAuTe4
TeTellurium
Teโ“˜ SylvaniteAgAuTe4
Teโ“˜ TellurobismuthiteBi2Te3
AuGold
Auโ“˜ Native Gold var. Electrum(Au,Ag)
Auโ“˜ Native GoldAu
Auโ“˜ SylvaniteAgAuTe4
PbLead
Pbโ“˜ GalenaPbS
BiBismuth
Biโ“˜ TellurobismuthiteBi2Te3

Other Regions, Features and Areas containing this locality

British and Irish IslesGroup of Islands
Eurasian PlateTectonic Plate
EuropeContinent
UK

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