Hemerdon Mine, also known as Hemerdon Ball Mine, Hemerdon Bal Mine and (briefly) previously as Drakelands Mine Mindat online database is a tungsten and tin mine. It is located northeast of Plymouth, near Plympton, in Devon, England. It lies to the north of the villages of Sparkwell and Hemerdon, and adjacent to the large china clay pits near Lee Moor. The mine had been out of operation since 1944, except for the brief operation of a trial mine in the 1980s. Work started to re-open it in 2014, but it ceased activities in 2018. It hosts the fourth largest tungsten deposit in the world.Tungsten and tin mine to reopen, BBC News, 4 December 2007, 09:12 GMT
A new company, Tungsten West plc acquired the site in 2019. A ground up review led to the recognition that the ore is not Wolframite, but is in fact a related ore, Ferberite, and changes were needed to improve extraction efficiencies. In addition, a subsidiary will enhance the mine with aggregate sales as a by-product of mining.Tungsten West plcThe operation has re-entered production as of 2026, with its strategic importance to critical mineral supply security cited as a major factor in achieving £71 million funding from the National Wealth Fund. The mine was designated as a strategic project under the EU's critical mineral strategy in 2025. Tungsten prices have increased over 8x since 2024, with shortages linked to the wars in Iran and Ukraine and the Chinese export restrictions. The USA has now banned exports of tungsten scrap as a national defense measure. Over 80% of global production is controlled by North Korea, China and Russia. Geology The Hemerdon deposit is centered upon a sub vertical, NNE-SSW striking, 100+ m wide Early Permian granite dyke hosted by Devonian metasedimentary and metavolcanic rocks. Mineralisation is overwhelmingly associated with moderately to steeply NW-dipping greisen-bordered quartz-ferberite± cassiterite sheeted veins. The resource size and dyke host are, to date, unique in SW England. The Hemerdon Ball granite is an outlying cupola intrusion surrounded by Devonian slates, known regionally as killas. Fractures in the granite and killas have been penetrated by mineralising fluids containing metallic ores in the area around the mine. Two types of vein are discernible with three different orientations. Quartz and quartz-feldspar veins form a stockwork with minor mineralisation, whilst greisen bordered veins are found in a sheeted vein system with ferberite and minor cassiterite mineralisation.CSM Virtual Museum Field Excursion
The mineralisation begins at surface and extends to depths of at least . The vein system is hosted in a dyke like granite body, extending from the Hemerdon Ball towards the Crownhill Down granite. It is flanked by killas, formed by contact metamorphism, which also contains veins although wolframite and cassiterite is found as a lower percentage of the rock bulk. Kaolinisation occurs to depths of up to in the granitic body.Wolf Minerals
The locality is renowned for its high quality scorodite specimens, which are among the best in Europe. Pharmacosiderite, Cassiterite, Ferberite and Wolframite of specimen quality have also been recovered from the mine. Scorodite and Pharmacosiderite are secondary arsenate minerals, that form in the upper oxidation zones of ore bodies. They are formed from alteration of arsenopyrite, and are found in the weathered zone of the deposit. At depths beneath the existing pit it is likely they will become scarce.Crystal Classics Article
History 1867–1959
The Hemerdon tungsten-tin deposit was discovered in 1867.Devon CMLP – IP38,Devon County Council In 1916, due to war associated tungsten shortages, an exploration and development programme was initiated, which outlined a tin-tungsten stockwork suitable for open-cast extraction. In 1917, Hemerdon Mines Ltd decided to construct a 140,000-tonne per year mill, and shortly afterwards open-cast ore mining operations began. The mine was operated in 1918–1919, during which time it processed 16,000 tonnes of ore. When the British government stopped accepting tungsten ores under the war pricing scheme the mine was forced to suspend mining operations.Cornwall’s Premier Tungsten Mine with brief comparative histories of other Wolfram Mines in Cornwall & West Devon, Cornish Hillside Publications, 2001, p128
Several attempts were made to establish a higher and stable price for tungsten from the government, including an application supported by Winston Churchill for recognition of wolfram mining as a key industry.Statement by WSC, Churchill Archives Centre However, after further price decreases, milling operations were suspended and the mill components were sold off.Terrell E. The Hemerdon Wolfram-Tin Mine, Mining Magazine February 1920, p75-87 In 1934 increased tungsten prices resulted in renewed prospecting of the deposit, along with metallurgical test work. In 1939 further shortages of tungsten due to WW2 led to Hemerdon Wolfram Ltd constructing a 90,000-tonne per year mill with 55% wolfram recovery, which began operation in 1941.Dines HG, The Metalliferous Mining Region of SW England, HMSO, 1956, p689
The Ministry of Supply carried out extensive evaluation of tungsten deposits in the UK, and it was concluded by 1942 that Hemerdon offered the most potential for producing tungsten on a large scale.Cameron J, The Geology of Hemerdon Wolfram Mine, Devon, IMM, Oct 1951, p1 The government took over the mine from Hemerdon Wolfram Ltd. A resource of 2.5 million tonnes of 0.14% tungsten trioxide in addition to tin was outlined, and a new plant was hastily constructed.
The new plant took over operation from the old plant in 1943, and theoretically should have been able to treat over 1 million tonnes per year; however labour shortages and mechanical faults resulted in a much lower production. Ore output from a mixture of underground and open-cast mining methods was documented as over 200,000 tonnes, with a resulting 180 tonnes of tin/tungsten concentrate during the period of government operation.Cameron J, The Geology of Hemerdon Wolfram Mine, Devon, IMM, Oct 1951, p121 Operations ceased in June 1944 due to access to overseas supplies being restored.Tungsten Mineral Resources Consultative Committee, HMSO, 1973, p8.
The plant was kept in place after the war, and the government was rumoured to have planned restarting production during the tungsten shortages associated with the Korean War.Mining Journal, 24 November 1950, p504 However, nothing came of this and following the Westwood Report in 1956, the government decided to seek a private partner to move the mine's development forwards. After further decreases in the tungsten price, resulting in the closure of the Castle-an-Dinas Mine tungsten mine in Cornwall, the government sold off all the plant in 1959.
1960–2006 However, in the mid-1960s work on the prospect was recommenced by British Tungsten Ltd, owned by Canadian entrepreneur W. A. Richardson. In 1969 a planning application for open-cast working of tin, tungsten and china clay was submitted, but it was withdrawn before a decision could be made. Further work commencing in 1970 by British Tungsten Ltd increased the resource to 5.6 million tonnes of ore.Perkins JW, Geology Explained: Dartmoor and the Tamar Valley, p71, 1972US Bureau of Mines, Minerals yearbook metals, minerals, and fuels 1970
The leases were transferred to Hemerdon Mining and Smelting Ltd in 1976. They initiated a drilling programme shortly before they entered a joint venture to develop the project with international mining firm AMAX in 1977.US Bureau of Mines, Minerals yearbook area reports: international 1977 An extensive exploration programme costing in excess of $10 million was completed between 1978 and 1980.Amax-Hemerdon Venture Evaluation Major Tin-Tungsten Property – Skillings Mining Review, vol.69, No.23, 7 June 1980 By the end of 1978, deeper drilling enlarged the resource size to 20 million tonnes of ore. In 1979 this was expanded to 45 million tonnes.US Bureau of Mines, Minerals yearbook area reports: international 1979 At the end of the exploration programme in 1980, over of diamond drilling had been undertaken, outlining a resource of 0.17% tungsten trioxide and 0.025% tin over 49.6 million tonnes.US Bureau of Mines, yearbook metals and minerals 1980
Bulk sampling of the deposit using an underground drift for ore, and a pilot HMS and Gravity plant for processing, was undertaken in 1980.US Bureau of Mines, Minerals yearbook metals and minerals 1980 On average recoveries of around 65% were made, although in excess of 70% was achieved. The final revision of the mining feasibility study concluded in 1982 that a within a global resource of 73 million tonnes of ore, at grades of 0.143% tungsten trioxide and 0.026% tin, there was an in pit reserve of 38 million tonnes, at grades of 0.183% tungsten trioxide and 0.029% tin.Feasibility Study for a Mine and Concentrator Complex at Hemerdon Nr Plymouth, England. Produced for AMAX/HMSL Joint Venture, February 1982
The venture was joined by Billiton Minerals Ltd, providing further finance and expertise, and forming a consortium that planned to commence production in 1986.US Bureau of Mines, Minerals yearbook area reports: international 1983 The initial planning application was made in 1981, but a public enquiry and 'calling in' of the application by the Secretary of State resulted in an initial refusal of the application in 1984.US Bureau of Mines, Minerals yearbook area reports: international 1984 This resulted in Billiton Minerals Ltd pulling out of the consortium.US Bureau of Mines, Minerals yearbook area reports: international 1985 Hemerdon Mining and Smelting Ltd also sold their 50% stake in the project to AMAX.Mining Journal, 19 April 1985 After making a revised application, permission was finally obtained in 1986. By then a collapse in the prices of both tin and tungsten had damaged the economic feasibility of making an investment in opening the mine. Its tungsten assets were passed on to a newly formed holding company, Canada Tungsten Ltd, in 1986.US Bureau of Mines, Minerals yearbook metals and minerals 1986
Canada Tungsten implemented the planning permission that was obtained in 1986, and kept the project in its portfolio of prospects for many years. Before AMAX was sold to Phelps Dodge, it gradually transferred Canada Tungsten into the ownership of Aur Resources. In 1997, a new company, North American Tungsten plc, purchased all the tungsten assets from Aur Resources, and was listed with the aim of reopening the Cantung mine, and developing the Hemerdon and Mactung prospects.Press Release 16 October 1997, North American Tungsten Corporation Ltd
However, during a review of peripheral assets in 1999, it decided that with the depressed prices of tungsten, the Hemerdon prospect was not central to its future. With upkeep costs of in excess of C$150,000 per annum, almost a third of the company's annual costs, attempts were made with the mineral rights holders to reduce fees. The negotiations were unsuccessful and therefore during 2000, two of the three mineral rights were surrendered.Long Form Prospectus, North American Tungsten Corporation Ltd, 14 May 2002 To further reduce costs, it disposed the remaining assets of the Hemerdon prospect in 2003.
The concrete roads constructed around the Second World War mills up to the open-cast area at the top of the hill were used by the Plymouth Motor Club and Plymouth Kart Club for speed hill climbs until approximately 1972.
2007–2018 Sustained tungsten metal price rises resulted in a five-fold increase in the price of ammonium paratungstate (an intermediate product of tungsten), from around US$60 per STU in 2003, to in excess of US$240 per STU from 2006.Tungsten Price Graph This has resulted in increased tungsten mining exploration and development activities globally since 2005.Tungsten AIMR Report 2007