Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite
Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
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Bryn-yr-Afr Mine, Ponterwyd, Trefeirig, Ceredigion, Wales, UKi
Regional Level Types
Bryn-yr-Afr MineMine (Abandoned)
Ponterwyd- not defined -
Trefeirig- not defined -
CeredigionCounty
WalesCountry
UKCountry

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Latitude & Longitude (WGS84):
52° 28' 23'' North , 3° 50' 52'' West
Latitude & Longitude (decimal):
UK National Grid Reference:
SN745878
Type:
Mine (Abandoned) - last checked 2020
Köppen climate type:
Nearest Settlements:
PlacePopulationDistance
Capel Bangor256 (2017)11.4km
Bow Street1,572 (2017)12.7km
Machynlleth2,235 (2017)13.1km
Borth1,269 (2017)13.8km
Aberdyfi725 (2017)15.5km
Mindat Locality ID:
4680
Long-form identifier:
mindat:1:2:4680:3
GUID (UUID V4):
0
Other/historical names associated with this locality:
Dyfed; Cardiganshire


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.


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


20 valid minerals.

Detailed Mineral List:

Albite
Formula: Na(AlSi3O8)
Habit: Tabular, twinned
Colour: White-colourless
Description: Colourless to white xls to 0.5mm, associated with apatite, rutile, quartz
References:
'Apatite'
Formula: Ca5(PO4)3(Cl/F/OH)
Habit: Tabular
Colour: Colourless-white
References:
Brochantite
Formula: Cu4(SO4)(OH)6
Habit: Thin bladed
Colour: Emerald green
Caledonite
Formula: Pb5Cu2(SO4)3(CO3)(OH)6
Habit: Thin drusey crusts
Colour: light blue
Description: Light blue xls to 0.4mm associated with hemimorphite.
References:
Cerussite
Formula: PbCO3
Habit: Various
Colour: White-colourless
Description: Xls to 1cm
Chalcopyrite
Formula: CuFeS2
Habit: Sphenoidal crystals, massive
Description: Very rare crystals to 6mm.
'Chlorite Group'
References:
Steve Rust collectionIdentified by Steve Rust: Visual Identification
Dolomite
Formula: CaMg(CO3)2
Habit: Massive
Colour: White-creamy, brown
Galena
Formula: PbS
Habit: Massive
Goethite
Formula: Fe3+O(OH)
Habit: Thin crusts
Hemimorphite
Formula: Zn4Si2O7(OH)2 · H2O
Habit: Bladed groups
Colour: Colourless
Description: Colourless bladed xls to 2mm
References:
Jamborite ?
Formula: Ni2+1-xCo3+x(OH)2-x(SO4)x · nH2O
Habit: Crusts
Colour: Yellowish green
Description: Occurs as a replacement of millerite
References:
Linarite
Formula: PbCu(SO4)(OH)2
Habit: Bladed
Marcasite
Formula: FeS2
Habit: Tabular, bladed
References:
Millerite
Formula: NiS
Habit: Acicular
Description: Acicular freegrown crystals to 5mm, and as embeded crystal to 5cms in massive sphalerite, with massive chalcopyrite.
References:
Muscovite
Formula: KAl2(AlSi3O10)(OH)2
Habit: Thin platy rossets
Description: Off white crystal rossets to 1mm, commly staind yellow and red by Fe oxides.
References:
Pyrite
Formula: FeS2
Habit: Cubic
Description: Large poorly crystalline masses with marcasite to 20cms + from the dumps. Very unstable specimens should be treated to retard pyrite/marcasite rot.
Pyromorphite
Formula: Pb5(PO4)3Cl
Habit: Prismatic
Colour: White-colourless, colour zoned colourless and brown.
References:
Quartz
Formula: SiO2
Habit: Pyramidle crystals
Colour: White-colourless, brown
Rutile
Formula: TiO2
References:
Smithsonite
Formula: ZnCO3
Habit: Botryoidal
Colour: White
Sphalerite
Formula: ZnS
Habit: Massive
Colour: Brown

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
Sphalerite2.CB.05aZnS
Chalcopyrite2.CB.10aCuFeS2
Millerite2.CC.20NiS
Galena2.CD.10PbS
Pyrite2.EB.05aFeS2
Marcasite2.EB.10aFeS2
Group 4 - Oxides and Hydroxides
Goethite4.00.Fe3+O(OH)
Quartz4.DA.05SiO2
Rutile4.DB.05TiO2
Jamborite ?4.FL.05Ni2+1-xCo3+x(OH)2-x(SO4)x · nH2O
Group 5 - Nitrates and Carbonates
Smithsonite5.AB.05ZnCO3
Dolomite5.AB.10CaMg(CO3)2
Cerussite5.AB.15PbCO3
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
Brochantite7.BB.25Cu4(SO4)(OH)6
Caledonite7.BC.50Pb5Cu2(SO4)3(CO3)(OH)6
Linarite7.BC.65PbCu(SO4)(OH)2
Group 8 - Phosphates, Arsenates and Vanadates
Pyromorphite8.BN.05Pb5(PO4)3Cl
Group 9 - Silicates
Hemimorphite9.BD.10Zn4Si2O7(OH)2 · H2O
Muscovite9.EC.15KAl2(AlSi3O10)(OH)2
Albite9.FA.35Na(AlSi3O8)
Unclassified
'Chlorite Group'-
'Apatite'-Ca5(PO4)3(Cl/F/OH)

List of minerals for each chemical element

HHydrogen
H BrochantiteCu4(SO4)(OH)6
H CaledonitePb5Cu2(SO4)3(CO3)(OH)6
H GoethiteFe3+O(OH)
H HemimorphiteZn4Si2O7(OH)2 · H2O
H JamboriteNi2+1-xCox3+(OH)2-x(SO4)x · nH2O
H LinaritePbCu(SO4)(OH)2
H MuscoviteKAl2(AlSi3O10)(OH)2
H ApatiteCa5(PO4)3(Cl/F/OH)
CCarbon
C CaledonitePb5Cu2(SO4)3(CO3)(OH)6
C CerussitePbCO3
C DolomiteCaMg(CO3)2
C SmithsoniteZnCO3
OOxygen
O AlbiteNa(AlSi3O8)
O BrochantiteCu4(SO4)(OH)6
O CaledonitePb5Cu2(SO4)3(CO3)(OH)6
O CerussitePbCO3
O DolomiteCaMg(CO3)2
O GoethiteFe3+O(OH)
O HemimorphiteZn4Si2O7(OH)2 · H2O
O JamboriteNi2+1-xCox3+(OH)2-x(SO4)x · nH2O
O LinaritePbCu(SO4)(OH)2
O MuscoviteKAl2(AlSi3O10)(OH)2
O PyromorphitePb5(PO4)3Cl
O QuartzSiO2
O RutileTiO2
O SmithsoniteZnCO3
O ApatiteCa5(PO4)3(Cl/F/OH)
FFluorine
F ApatiteCa5(PO4)3(Cl/F/OH)
NaSodium
Na AlbiteNa(AlSi3O8)
MgMagnesium
Mg DolomiteCaMg(CO3)2
AlAluminium
Al AlbiteNa(AlSi3O8)
Al MuscoviteKAl2(AlSi3O10)(OH)2
SiSilicon
Si AlbiteNa(AlSi3O8)
Si HemimorphiteZn4Si2O7(OH)2 · H2O
Si MuscoviteKAl2(AlSi3O10)(OH)2
Si QuartzSiO2
PPhosphorus
P PyromorphitePb5(PO4)3Cl
P ApatiteCa5(PO4)3(Cl/F/OH)
SSulfur
S BrochantiteCu4(SO4)(OH)6
S CaledonitePb5Cu2(SO4)3(CO3)(OH)6
S ChalcopyriteCuFeS2
S GalenaPbS
S JamboriteNi2+1-xCox3+(OH)2-x(SO4)x · nH2O
S LinaritePbCu(SO4)(OH)2
S MarcasiteFeS2
S MilleriteNiS
S PyriteFeS2
S SphaleriteZnS
ClChlorine
Cl PyromorphitePb5(PO4)3Cl
Cl ApatiteCa5(PO4)3(Cl/F/OH)
KPotassium
K MuscoviteKAl2(AlSi3O10)(OH)2
CaCalcium
Ca DolomiteCaMg(CO3)2
Ca ApatiteCa5(PO4)3(Cl/F/OH)
TiTitanium
Ti RutileTiO2
FeIron
Fe ChalcopyriteCuFeS2
Fe GoethiteFe3+O(OH)
Fe MarcasiteFeS2
Fe PyriteFeS2
CoCobalt
Co JamboriteNi2+1-xCox3+(OH)2-x(SO4)x · nH2O
NiNickel
Ni JamboriteNi2+1-xCox3+(OH)2-x(SO4)x · nH2O
Ni MilleriteNiS
CuCopper
Cu BrochantiteCu4(SO4)(OH)6
Cu CaledonitePb5Cu2(SO4)3(CO3)(OH)6
Cu ChalcopyriteCuFeS2
Cu LinaritePbCu(SO4)(OH)2
ZnZinc
Zn HemimorphiteZn4Si2O7(OH)2 · H2O
Zn SmithsoniteZnCO3
Zn SphaleriteZnS
PbLead
Pb CaledonitePb5Cu2(SO4)3(CO3)(OH)6
Pb CerussitePbCO3
Pb GalenaPbS
Pb LinaritePbCu(SO4)(OH)2
Pb PyromorphitePb5(PO4)3Cl

Other Regions, Features and Areas containing this locality

British and Irish IslesGroup of Islands
Eurasian PlateTectonic Plate
EuropeContinent
UK

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