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Drakelands Mine (Hemerdon Mine; Hemerdon Bal Mine; Hemerdon Ball Mine), Plympton, Plymouth, Devon, England, UK

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Latitude & Longitude (WGS84): 50° 24' 26'' North , 4° 0' 35'' West
Latitude & Longitude (decimal): 50.40749,-4.00985
GeoHash:G#: gbvnub2hg
UK National Grid Reference:SX572584
Owned/operated by:Wolf Minerals
Locality type:Mine
Köppen climate type:Cfb : Temperate oceanic climate


An open-cast tungsten mine near Plymouth in Devon - this locality is famed for its high-quality scorodite (among the best in Europe) with ferberite and cassiterite. The deposit was sampled in 1982 by AMAX but problems were encountered due to the difficulty of separating the clays from the ore.

On 4th December 2007, it was announced that an Australian company, Wolf Minerals LLC, had acquired the rights to mine this deposit, and current plans are to reopen the site as a full-scale open cast metal mine for tungsten and tin, producing up to 3000 tonnes of tungsten metal per year.

The mine restarted production in August 2015 with the first tungsten concentrate in 45 years leaving the deposit.

The mine ceased operating on October 10th, 2018 after Wolf Minerals (UK) Ltd went into voluntary administration. It is currently (October 2018) seeking further investment to restart operations.

The original name for the workings was "Hemerdon Bal", this was corrupted over time (possibly due to a mis-spelling on Ordnance Survey maps that remains to this day) to "Hemerdon Ball". *

* It is worth noting that the name Hemerdon Ball, which is the name of the hill, is shown on OS mapping surveyed and published between 1854 and 1863. Whilst some shafts of what is the Woolcombe Mine are identified on this old mapping lying to the west of the current Hemerdon site, this considerably pre-dates the identification and initial defining and working of the tin-tungsten deposit in around 1916, although the presence of tungsten mineralisation had been observed in a small quarry on Hemerdon Ball in the latter half of the 19th century. Indeed it would seem more likely that Hemerdon Bal is a corruption of the older place name rather than the original name of the workings.

Alternative Label Names

This is a list of additional names that have been recorded for mineral labels associated with this locality in the minID database. This may include previous versions of the locality name hierarchy from mindat.org, data entry errors, and it may also include unconfirmed sublocality names or other names that can only be matched to this level.

Hemerdon Mine (Hemerdon Bal Mine; Hemerdon Ball Mine), Plympton, Tavistock District, Devon, England, UK
Hemerdon ball mine Sparkwell Devon

Regions containing this locality

Devon and Cornwall metalliferous mining district, England, UK

Mining District - 759 mineral species & varietal names listed

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Commodity List

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


Mineral List


17 valid minerals.

Detailed Mineral List:

'Alumotungstite'
Formula: 2W2O6(H2O)
Reference: Bernard & Hyrsl (2004) Minerals and their Localities. (Granit, Prague); Steve Rust, Richard de Nul, and Gunnar Färber specimens.
Arsenopyrite
Formula: FeAsS
Description: Silvery masses to several cms commonly partly to completely altered to scorodite.
Reference: No reference listed
Cassiterite
Formula: SnO2
Description: Rarely found as black well formed crystals to 1.5cms, occasionally as sparable tin micro-crystals to 1.5mm. Also as small veinlets to over 20cms long, and small clots to afew cms. The deposite is said to contain about 0.2% tin concentrate.
Reference: Mineralogical Record (2001) 32:249
Ferberite
Formula: FeWO4
Description: Extreamly rare as free grown crystals to 1.5cm, common as micro-crystals. Also common as bladed crystals to over 10cm embeded in quartz.
Reference: Richard de Nul, Steve Rust, and Chris Popham specimens.
Goethite
Formula: α-Fe3+O(OH)
Description: Common as an alteration of hematite, and ferberite.
Hematite
Formula: Fe2O3
Description: Mostly seen as black lenticular micro-crystals to 1mm as single crystals, and forming inter-grown aggregates to several cms. Commonly with an iridescent tarnish.
Reference: No reference listed
Hydrokenoelsmoreite
Formula: 2W2O6(H2O)
Description: Occasionally found associated with ferberite or near to this mineral. Hydrokenoelsmoreite is very esaly over looked at this location due to its mica like habit, or looks like kaolinite. Thin platy micro-crystals have been found covering several cms. The colour varies from white to light yellow and pale brown, probably due to Fe contamination.
Reference: Mills, S.J., Christy, A.G., Rumsey, M.S., Spratt, J. (2016): The crystal chemistry of elsmoreite from the Hemerdon (Drakelands) mine, UK: hydrokenoelsmoreite-3C and hydrokenoelsmoreite-6R. Mineralogical Magazine, 80, 1195-1203.
Hydrokenoelsmoreite var: Ferritungstite
Reference: Steve Rust and Richard de Nul specimens.
Kaolinite
Formula: Al2(Si2O5)(OH)4
Description: A very common white clay in the deposit making it difacult to procces the ore.
Reference: Steve Rust Collection
Lepidocrocite
Formula: γ-Fe3+O(OH)
Description: small group of black mm-sized crystals, the thinnest crystals seen to be yellow under the microscope
Reference: Identified by Tom Cotterell at the National Museum of Wales
'Limonite'
Formula: (Fe,O,OH,H2O)
Reference: Paul De Bondt collection;
Malachite
Formula: Cu2(CO3)(OH)2
Reference: Collection Richard De Nul
Molybdenite
Formula: MoS2
Description: Bright silvery metallic micro-flakes associated with wolframite, quartz, arsenopyite, muscovite, tourmaline and scorodite.
Reference: S.Rust Collection;
Muscovite
Formula: KAl2(AlSi3O10)(OH)2
Description: A major mineral in the greisen tungsten/tin deposit along with quartz and tourmaline. Cavitys are commonly lined with typical hexagonal books of muscovte crystals to 5mm across the 'C' face. The colour is mostly white-silvery to stained shades of brown by Fe oxides.
Reference: Steve Rust Collection
Pharmacosiderite
Formula: KFe3+4(AsO4)3(OH)4 · 6-7H2O
Description: Not uncommon as cubic crystals to 1mm, rare as crystals over 1.5mm. The colour varies from almost colourless to light green, yellow-brown, and yellow.
Reference: Mineralogical Record (2001) 32:249
'Plumbogummite Group'
Description: The partly defined mineral forms tiny micro-crystals to 0.25mm with a pseudocubic habit, and a white to flesh pink colouration. Associated with cassiterite and tourmaline on quartz.
Reference: Steve Rust Collection
Pyrite
Formula: FeS2
Reference: Paul De Bondt collection
Quartz
Formula: SiO2
Description: Occasionally forms prismatic crystals to 10cm.
Reference: P Haas collection; Mineralogical Record (2001) 32:249
Russellite
Formula: Bi2WO6
Description: Rarely found as pale to light yellow botryoidal crusts to 1cm, or as scattered balls to 0.75mm dia.
Reference: Mineralogical Record (2001) 32:249
Scorodite
Formula: Fe3+AsO4 · 2H2O
Description: Some of the best examples of scorodite have come from this mine over the years, and looks set to produce further specimens when mining starts in 2012/13. Exceptional scorodite crystals have been found to about 1cm, more useul as blue to greenish druse of crystals lining cavitys to many cms in the quartz veinstone.
Reference: Mineralogical Record (2001) 32:249
Sulphur
Formula: S8
Description: Rounded very pale yellow micro-crystals to 0.5mm associated with granular white to pale green scorodite, with cassiterite on quartz, and minor ferberite.
Reference: Steve Rust Collection
'commodity:Tin'
Formula: Sn
Reference:  
'Tourmaline'
Formula: A(D3)G6(T6O18)(BO3)3X3Z
Description: Forms as a major mineral in veins to 10 of mts long. Free grown crystals are seldom more than 1cm long. The colour is mostly black in the hand specimen, whiel under the micrscope the colour is seen to be much more varied from almost colourless to blue and brown and black.
Reference: No reference listed
'commodity:Tungsten'
Formula: W
Reference:  

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
Sulphur1.CC.05S8
Group 2 - Sulphides and Sulfosalts
'Arsenopyrite'2.EB.20FeAsS
Molybdenite2.EA.30MoS2
Pyrite2.EB.05aFeS2
Group 4 - Oxides and Hydroxides
'Cassiterite'4.DB.05SnO2
'Ferberite'4.DB.30FeWO4
Goethite4.00.α-Fe3+O(OH)
Hematite4.CB.05Fe2O3
Hydrokenoelsmoreite4.DH.152W2O6(H2O)
var: Ferritungstite4.DH.152W2O6(H2O)
Lepidocrocite4.FE.15γ-Fe3+O(OH)
Quartz4.DA.05SiO2
Russellite4.DE.15Bi2WO6
Group 5 - Nitrates and Carbonates
Malachite5.BA.10Cu2(CO3)(OH)2
Group 8 - Phosphates, Arsenates and Vanadates
Pharmacosiderite8.DK.10KFe3+4(AsO4)3(OH)4 · 6-7H2O
Scorodite8.CD.10Fe3+AsO4 · 2H2O
Group 9 - Silicates
Kaolinite9.ED.05Al2(Si2O5)(OH)4
Muscovite9.EC.15KAl2(AlSi3O10)(OH)2
Unclassified Minerals, Rocks, etc.
'Alumotungstite'-2W2O6(H2O)
Limonite-(Fe,O,OH,H2O)
Plumbogummite Group-
Tourmaline-A(D3)G6(T6O18)(BO3)3X3Z

List of minerals arranged by Dana 8th Edition classification

Group 1 - NATIVE ELEMENTS AND ALLOYS
Semi-metals and non-metals
Sulphur1.3.5.1S8
Group 2 - SULFIDES
AmBnXp, with (m+n):p = 1:2
Arsenopyrite2.12.4.1FeAsS
Molybdenite2.12.10.1MoS2
Pyrite2.12.1.1FeS2
Group 4 - SIMPLE OXIDES
A2X3
Hematite4.3.1.2Fe2O3
AX2
Cassiterite4.4.1.5SnO2
Group 6 - HYDROXIDES AND OXIDES CONTAINING HYDROXYL
XO(OH)
Goethite6.1.1.2α-Fe3+O(OH)
Lepidocrocite6.1.2.2γ-Fe3+O(OH)
Group 16a - ANHYDROUS CARBONATES CONTAINING HYDROXYL OR HALOGEN
Malachite16a.3.1.1Cu2(CO3)(OH)2
Group 40 - HYDRATED NORMAL PHOSPHATES,ARSENATES AND VANADATES
(AB)5(XO4)2·xH2O
Scorodite40.4.1.3Fe3+AsO4 · 2H2O
Group 42 - HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
(AB)5(XO4)3Zq·xH2O
Pharmacosiderite42.8.1a.1KFe3+4(AsO4)3(OH)4 · 6-7H2O
Group 48 - ANHYDROUS MOLYBDATES AND TUNGSTATES
AXO4
Ferberite48.1.1.2FeWO4
A2XO4
Russellite48.2.1.1Bi2WO6
Group 71 - PHYLLOSILICATES Sheets of Six-Membered Rings
Sheets of 6-membered rings with 2:1 layers
Muscovite71.2.2a.1KAl2(AlSi3O10)(OH)2
Group 75 - TECTOSILICATES Si Tetrahedral Frameworks
Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si
Quartz75.1.3.1SiO2
Unclassified Minerals, Rocks, etc.
'Alumotungstite'-2W2O6(H2O)
Hydrokenoelsmoreite-2W2O6(H2O)
var: Ferritungstite-2W2O6(H2O)
Kaolinite-Al2(Si2O5)(OH)4
'Limonite'-(Fe,O,OH,H2O)
'Plumbogummite Group'-
'Tourmaline'-A(D3)G6(T6O18)(BO3)3X3Z

List of minerals for each chemical element

HHydrogen
H Alumotungstite2W2O6(H2O)
H Goethiteα-Fe3+O(OH)
H Hydrokenoelsmoreite2W2O6(H2O)
H KaoliniteAl2(Si2O5)(OH)4
H Lepidocrociteγ-Fe3+O(OH)
H Limonite(Fe,O,OH,H2O)
H MalachiteCu2(CO3)(OH)2
H MuscoviteKAl2(AlSi3O10)(OH)2
H PharmacosideriteKFe43+(AsO4)3(OH)4 · 6-7H2O
H ScoroditeFe3+AsO4 · 2H2O
BBoron
B TourmalineA(D3)G6(T6O18)(BO3)3X3Z
CCarbon
C MalachiteCu2(CO3)(OH)2
OOxygen
O Alumotungstite2W2O6(H2O)
O CassiteriteSnO2
O FerberiteFeWO4
O Goethiteα-Fe3+O(OH)
O HematiteFe2O3
O Hydrokenoelsmoreite2W2O6(H2O)
O KaoliniteAl2(Si2O5)(OH)4
O Lepidocrociteγ-Fe3+O(OH)
O Limonite(Fe,O,OH,H2O)
O MalachiteCu2(CO3)(OH)2
O MuscoviteKAl2(AlSi3O10)(OH)2
O PharmacosideriteKFe43+(AsO4)3(OH)4 · 6-7H2O
O QuartzSiO2
O RusselliteBi2WO6
O ScoroditeFe3+AsO4 · 2H2O
O TourmalineA(D3)G6(T6O18)(BO3)3X3Z
AlAluminium
Al KaoliniteAl2(Si2O5)(OH)4
Al MuscoviteKAl2(AlSi3O10)(OH)2
SiSilicon
Si KaoliniteAl2(Si2O5)(OH)4
Si MuscoviteKAl2(AlSi3O10)(OH)2
Si QuartzSiO2
SSulfur
S ArsenopyriteFeAsS
S MolybdeniteMoS2
S PyriteFeS2
S SulphurS8
KPotassium
K MuscoviteKAl2(AlSi3O10)(OH)2
K PharmacosideriteKFe43+(AsO4)3(OH)4 · 6-7H2O
FeIron
Fe ArsenopyriteFeAsS
Fe FerberiteFeWO4
Fe Goethiteα-Fe3+O(OH)
Fe HematiteFe2O3
Fe Lepidocrociteγ-Fe3+O(OH)
Fe Limonite(Fe,O,OH,H2O)
Fe PharmacosideriteKFe43+(AsO4)3(OH)4 · 6-7H2O
Fe PyriteFeS2
Fe ScoroditeFe3+AsO4 · 2H2O
CuCopper
Cu MalachiteCu2(CO3)(OH)2
AsArsenic
As ArsenopyriteFeAsS
As PharmacosideriteKFe43+(AsO4)3(OH)4 · 6-7H2O
As ScoroditeFe3+AsO4 · 2H2O
MoMolybdenum
Mo MolybdeniteMoS2
SnTin
Sn CassiteriteSnO2
WTungsten
W Alumotungstite2W2O6(H2O)
W FerberiteFeWO4
W Hydrokenoelsmoreite2W2O6(H2O)
W RusselliteBi2WO6
BiBismuth
Bi RusselliteBi2WO6

Regional Geology

This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.

Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org

Permian
251.902 - 298.9 Ma



ID: 3193041
Paleozoic intrusive rocks

Age: Phanerozoic (251.902 - 298.9 Ma)

Lithology: Intrusive igneous rocks

Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. [154]

Devonian
358.9 - 419.2 Ma



ID: 2026623
Unnamed Igneous Intrusion, Devonian

Age: Devonian (358.9 - 419.2 Ma)

Lithology: Felsic-rock

Reference: British Geological Survey. DiGMapGB-625. British Geological Survey ©NERC. [23]

Late Devonian
358.9 - 382.7 Ma



ID: 3132501
Late Devonian claystone

Age: Late Devonian (358.9 - 382.7 Ma)

Lithology: Claystone

Reference: Asch, K. The 1:5M International Geological Map of Europe and Adjacent Areas: Development and Implementation of a GIS-enabled Concept. Geologisches Jahrbuch, SA 3. [147]

Data and map coding provided by Macrostrat.org, used under Creative Commons Attribution 4.0 License

References

Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Mills, S.J., Christy, A.G., Rumsey, M.S., and Spratt, J. (2016) The crystal chemistry of elsmoreite from the Hemerdon (Drakelands) mine, UK: hydrokenoelsmoreite-3C and hydrokenoelsmoreite-6R. Mineralogical Magazine, 80, 1195-1203.

Documents

Title (click to view)YearAuthor
The Hemerdon Project (Drakelands) Information Pack2014Wolf Minerals

External Links



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