Open questions: Cornwall

Where sources disagree, MineArchive keeps both accounts rather than picking one; where a fact could not be settled, the record says so. 124 such claims on 61 records. All regions.

Balleswidden Mine

The Penwith Local History Group gives 1873 for the mine's closure; Cornwall Calling says it worked until 1875; Buddlepit lists working periods to 1878. (disputed)

Basset and Grylls Mine

Between 1852 and 1880 it produced 4,323 tons of tin. (disputed)
Working from 1852 to 1914 it produced 4,650 tons of tin. (disputed)

Boscean Mine

Cornwall Calling has the Wheal Owles miners breaking into flooded workings of Boscean Mine in 1893; Wikipedia has them breaking into the flooded workings of Wheal Drea, which had been flooded by water from Boscean. (disputed)

Botallack Mine

The mine is generally described as closing in 1895 on falling tin and copper prices; some secondary accounts instead describe operations continuing in reduced form to 1914. (disputed)
Prince Arthur descended the Boscawen Diagonal Shaft on 15 May 1862 and the Prince and Princess of Wales in 1865, in the same gig involved in the 1863 accident; R. M. Ballantyne visited in 1868 and drew on it for his novel Deep Down. (uncertain)
At its height under Stephen Harvey James's ownership the mine employed over 550 people, 340 of them underground. (uncertain)

Cligga Head

A 2019 underground exploration report describes a recent collapse in the giant stope at Cligga Head and unstable ground in places, with a short modern ladder used to pass between the stope and the middle level. (uncertain)
An account published in 2024 of a guided descent made in August 2010 describes ladders and tight passages, a surviving Cousin Jack chute, and mineral staining across the cliff face where the fissures and adits that drained the mine to sea level break out; extensive remains of open works, buildings, shafts and spoil tips survive on the headland. (uncertain)
After the 1945 closure the mine was reopened between 1962 and 1965, and further attempts at revival came to nothing once the tin price collapsed in 1985. (uncertain)

Consolidated Mines

Wikipedia dates Consolidated Mines' formation to 1782, from the merger of Wheal Virgin, West Wheal Virgin, Wheal Girl, Wheal Maid, Wheal Fortune and Carharrack Mine. (disputed)
Cornwall Calling instead dates the mine's formation to 1780. (disputed)
Wikipedia records Consolidated Mines ceasing work in 1857 and amalgamating with United Mines and Wheal Clifford in 1861 to form Clifford Amalgamated Mines, which continued unprofitably until 1870; Grace’s Guide gives the closure as 1858 and the amalgamation with United as 1857. (disputed)

Crenver & Wheal Abraham

The mine traded as the Crenver and Wheal Abraham United Mining Co. Ltd. (also recorded as Crenver and Wheal Abraham United Mines Co. Ltd.), appearing in Parliamentary returns of registered Cornish and Devon joint-stock mining companies during the 1860s. (uncertain)

Dolcoath Mine

Grace's Guide records Dolcoath as producing over 350,000 tons of copper across its working life and over 100,000 tons of tin between 1853 and 1920, and values total mineral production at over £10 million — against the figure of over £9 million for 1799-1920 given elsewhere. The two are not directly comparable, covering different periods. (disputed)
Sources disagree on the closing year: most give 1920, while Grace's Guide records operations ceasing in 1921. (disputed)

Drakewalls Mine

It was worked from the 11th century to 1905 (also 1909-10), originally from a long gunnis or open cutting. (uncertain)

Dria Quarry

There is no processing area above the quarry, so its dressing was probably shared with Bagalow Quarry, and the small platform shown on the 1880s map suggests the lifting may have been shared too. (uncertain)
The name may be a form of tre, a farmstead, perhaps from a settlement once on the cliffs near the cove. (uncertain)

East Pool Mine

Sources disagree on the date the Taylor's Shaft pumping engine was built: the National Trust's own record gives 1891, built by Harvey & Co of Hayle for £5,500 and first installed at Highburrow East Shaft, Carn Brea, while Wikipedia gives 1892. Both agree it was re-erected at Taylor's Shaft in 1924. (disputed)
Sources also disagree on when the Taylor's Shaft engine stopped: the National Trust records it working from 1925 until 1955, while Wikipedia gives 28 September 1954 as the date electric pumps took over. (disputed)

East Wheal Lovell

East Wheal Lovell worked from 1859 to 1891, producing 2,405 tons of tin. (disputed)
The yearly production table for 1859-1891 totals 1,846.7 tons of black tin worth £121,579. (disputed)
East Wheal Lovell operated until 1881 and reportedly had the last steam beam engine to work in the Wendron district. (disputed)

East Wheal Rose

The Mining Remediation Authority holds abandonment plan OMR77D for silver-lead ore at Wheal Rose. (uncertain)

Fowey Consols

Joseph Treffry took control of the group of five mines known as Fowey Consols in 1819. (disputed)
The mines stopped in 1819 and were bought by Treffry in 1822 and consolidated as Fowey Consols; Lanescot was added in 1836. (disputed)
Between 1822 and 1867 the mine produced over 315,000 tons of 8 per cent copper ore. (disputed)
With Lanescot the mine produced 382,910 tonnes of ore from 1822 to 1867. (disputed)

Geevor Tin Mine

A 2024 report on the preserved site describes lockers in the mine's ‘dry’ (changing room) still marked with the mine's closure date, some still holding personal items and work clothing. (uncertain)

Giew Mine

The engine house was erected in 1871. (disputed)
The engine house bears a datestone of 1874 with the initials SP. (disputed)
Frank's shaft is 1,464 feet deep. (disputed)
Frank's shaft is 225 metres deep. (disputed)

Gravel Hill Mine

Originally known as Penhale Iron Mine, Gravel Hill is known to have been at work before 1728, also in the 1840s, and from 1874-82. (disputed)
Gravel Hill Mine was first known as Penhale Iron Mine, with operations commencing about 1840. (disputed)
The last working produced about 8,000 tons of iron ore and 30 tons of zinc ore, and more than 35,000 tons of spathose ore were raised during the mine's life. (disputed)
Between 1874 and 1882 Gravel Hill produced 7,400 tons of brown iron ore at 47% iron, 10,379 tons of mixed limonite and spathic ores and 30 tons of zinc ore at 40%; 165 tons of brown iron ore returned in 1866 as Perran Bay may refer to the cliff workings. (disputed)

Great Carnon Stream Works

The Survey's account has the deposits worked before 1800 by embanking certain areas to hold back the tidal water, and the tide breaking through about that year, at which point the works were abandoned. (disputed)
The local accounts have the Great Carnon works at their height in 1797 and ended in 1812, when a severe gale combined with an exceptionally high tide breached the dam. (disputed)
One nugget from the Carnon Valley is recorded as weighing 1 ounce 18 pennyweight and 8.6 grains - about 60 grams - which is more than three times the figure of around 18 grams given for the largest single nugget from the Great Carnon works itself. The two may not describe the same find or the same working. (disputed)

Great Crinnis Mine

A later account put the copper ore raised in 1803–28 at about £1,400,000, with profits of about £400,000, from a small part of a central lode 17 to 24 feet wide; the figures were reported as estimates. (uncertain)
Mindat records two lodes cropping out in the cliffs, marked by old dumps on the golf course; the mine was reputed to have raised over 70,000 tons of copper ore before 1830 from shallow depth, with only small amounts later, and closed in 1881. (uncertain)

Great Dowgas Mine

Great Dowgas Mine is first recorded selling a small quantity of black tin around 1719; no earlier production figures survive, and the mine was reworked repeatedly, without great success, until 1913. (uncertain)

Great Work Mine

In 1930 the mine closed with some miners continuing to work above adit level; it was de-watered in the mid-1930s in an attempt to reopen it, and closed permanently in 1939 per Wikipedia. A more detailed account gives the final attempt as Great Work Tin Mines Ltd from 1935, de-watering the Deerpark shaft before abandoning it and allowing the lower workings to flood again, with work stopping for the last time in 1938. Both accounts describe the same closing episode; the exact final year is not fully reconciled between them. (disputed)
Great Work had opened by 1538. By 1584 the mine is recorded as employing at least 300 people with annual profits of around £1000 (Aslet, 2010). A higher, uncited figure of over 3,000 workers for the same late-16th-century period appears on some tourism-oriented sites (gooseygoo.co.uk, a Geograph photo caption) but is uncited and no other account repeats it. (uncertain)
Ownership of the mine passed from the Godolphin family to the Duke of Leeds in 1785; the mine's principal shaft, Leeds shaft, takes its name from this change of proprietor. (uncertain)
The mine closed in 1793 as the price of tin fell, before being revived in 1810 as a major copper producer. (uncertain)
The mine was worked again as Old Great Works between 1890 and 1902, as South West Cornwall Mines from 1907 to 1912, and from 1927 alongside neighbouring Wheal Reeth for about ten years. (uncertain)
Mining engineer W. J. Henwood recorded in 1843 that where the Wheal Breage lode passed from granite into the surrounding greenstone (killas), the tin ore it carried disappeared instantly — a specific, documented illustration of the tin mineralisation being concentrated within the granite host. (uncertain)

Gunnislake Clitters Mine

Cornwall Calling gives the mine as worked from 1820 to 1919, first by an adit from the valley side and later by shafts; the Durham Mining Museum records it as opened in 1860 and closed in 1889, which matches the life of the Gunnislake Clitters Mining Co. (disputed)
The BGS mine-plans catalogue holds a Mining Remediation Authority abandonment plan titled 'Gunnislake Clitters' (catalogue OMR63A, Tin Copper And Arsenic Ores, dated 1889); the catalogue gives no location and the plan's details do not clearly tie it to this working, so it may belong to another of the same name. (uncertain)

Hallenbeagle Mine

Sources disagree on the pumping engine's exact size: Explore Cornwall records it as a 60-inch engine, while a Geograph caption for the same building notes that sources differ between 60 and 70 inches. (disputed)
A smaller 22-inch whim engine also worked the mine and was moved on to Dooneen Mine in Ireland by 1872. Explore Cornwall places this engine at Reed's Shaft alongside the pumping engine; Cornish Mine Images instead places it at a separate Doctor's Shaft. (disputed)
Just before the 1870s Hallenbeagle was reported worked jointly again, this time with East Downs Mine — reported by Explore Cornwall only. (uncertain)

Hobbs Hill Tin Mine

The lodeback tinwork west of the mine may be the 'Hobbys Worke' recorded by 1516. (uncertain)

Holmbush Mine

The BGS mine-plans catalogue holds a BGS plan titled 'Holmbush' (catalogue MP24157, undated in the catalogue); the catalogue gives no location and the plan's details do not clearly tie it to this working, so it may belong to another of the same name. (uncertain)

Levant Mine

Documented mining at Levant dates from April 1787; claims that the site was worked as early as the Roman period (around 200 AD) are not backed by firm evidence. (uncertain)
Over its working life Levant produced in excess of 130,000 tons of copper and 24,000 tons of tin, along with substantial arsenic. (uncertain)
The company was restructured as Levant Tin Mines Limited in 1920 under Colonel F. F. Oats. (uncertain)
Seawater was found to have broken into the abandoned workings at the 40 fathom level; two sealing attempts in the 1950s were needed before the breach was closed in the 1960s. (uncertain)
Geevor reopened Levant's undersea ground in November 1980 by way of an inclined shaft driven at about 25 degrees, working it until Geevor itself closed. (uncertain)

Nangiles Mine

By 1864 the mine had reached 117 fathoms below adit and was equipped with a 30-inch stamps engine and a winding engine in addition to the pumping engine; a separate 36-inch stamps engine was installed in 1871 by the Welsh Gold Mining Company, driving 84 stamp heads, and was sold on to West Condurrow in 1891. (uncertain)
The ground was investigated and worked for tin again by the Wheal Jane group in 1969–79 and 1980–91, alongside Wheal Jane's own much larger contemporary operation nearby. (uncertain)

Parkenoweth Mine

Parkenoweth was one of the constituent lodes/workings of the wider Wheal Owles group at Botallack, alongside Wheal Edward, Wheal Grouse, Cargodna, Wheal Boys, Wheal Gendall, Wheal Chase and Lower Boscean. (uncertain)

Pednandrea Mine

It reopened in 1854 and stayed open until 1891. (disputed)
Pednandrea United was abandoned in 1880. (disputed)

Penberthy Croft Mine

Sources put the working life differently. The Geological Conservation Review has the mine producing very little by 1840 and believed closed in the late 1840s, but records output again in 1881-83; mine databases give the span as 1798 to 1883, and a 2021 field note says simply that it closed in 1840. (disputed)

Pendarves Mine

One account says lack of money and development forced Pendarves to close in 1984, when the bulk of its available ore reserves had been exhausted. (disputed)
Another says Carnon Consolidated closed Pendarves, which had supplied ore to the South Crofty mill since at least 1975, when it rationalised its operations after the October 1985 tin price collapse. (disputed)

Penhalls Mine

The BGS mine-plans catalogue holds a Mining Remediation Authority abandonment plan titled 'Penhalls' (catalogue OMR118C, Tin And Copper Ores, dated 1880); the catalogue gives no location and the plan's details do not clearly tie it to this working, so it may belong to another of the same name. (uncertain)

Phoenix United Mine

West Phoenix Mine was included in the sett in 1875, after which the mine was worked as Phoenix United. (disputed)
Phoenix took over West Phoenix completely in 1886, working under the name Phoenix United again. (disputed)
Seccombe's shaft was 125 fathoms deep, the Old Sump 216 fathoms, Anne's 112 fathoms and Hamilton's 40 fathoms. (uncertain)

Polberro Mine

Over its main working period the mine produced 4,310 tons of tin and 1,598 tons of copper. (uncertain)

Polhigey Mine

In 1850 Polhigey Moor Mine was described as working by streaming and shallow lode mining. (uncertain)

Poltesco Serpentine Works

The business wound up in 1893 after the loss of an uninsured cargo at sea, combined with a decline in the fashion for serpentine ornament. (uncertain)
Most of the works were demolished in the 1930s by a Mr Ironside, after a Council for the Preservation of Rural England survey recommended converting the buildings to holiday accommodation. (uncertain)
Serpentine slabs from the works were used in Duchy of Cornwall buildings in London, with company showrooms near the Strand; finished goods were shipped through Penryn and Falmouth. (uncertain)

Prince of Wales Quarry, Trebarwith

Built in 1870 for a fifty-inch Woolf compound beam engine that pumped the pit and hauled slate. (disputed)
Completed in 1872 for a fifty-inch Harvey engine that pumped the pit until 1890 and hauled trucks from Bowithick quarry across the valley. (disputed)

Rosemanowes Quarry

Wikipedia dates the trials to 1977–1980 with studies continuing to 1991; Law et al. (2019) describe the Camborne School of Mines programme as running from the late 1970s to the early 1990s, with three deep wells drilled during the first half of the 1980s. (uncertain)

South Crofty

A 2008 report on Robinson's Shaft describes the winding house as roofless and deteriorating despite being otherwise complete, and the bathhouse as retaining period fittings including a lamp rack, 1970s safety posters and showers. (uncertain)

South Terras Mine

It is often stated that Marie Curie herself sourced early radium samples from South Terras; the better-documented historical connection is through Marcel Pochon (a former assistant to her husband Pierre Curie) and the London Radium Institute, and this stronger claim about Marie Curie personally has not been independently confirmed here. (disputed)

Ting Tang Mine

The mine's principal shafts were Eldon's, Taylor's and Garland's shafts. (uncertain)
Ting Tang was one of the important copper-producing concerns in the Gwennap district, with production of approximately 40,000 tons of ore recorded during its operational period; chief produce was copper, alongside pyrites and malachite. (uncertain)
A Wikimedia Commons specimen description independently records Ting Tang as 'an active mine from 1816-1865' — consistent with, though not identical to, the c.1816-1847 copper production window commonly attributed to H.G. Dines in third-party summaries. (uncertain)
In 1861 Ting Tang was drawn into a large combination with the Consolidated Mines, United Mines, Wheal Clifford and Wheal Squire, known as the Clifford Amalgamated Mines — a name and grouping already recorded on this site's Clifford Amalgamated Mines operator page, whose own account dates the underlying merger of Consolidated Mines and United Mines to 1857. The two accounts are not necessarily contradictory: read together they suggest an initial 1857 merger of the two largest setts, expanded in 1861 to formally bring in Ting Tang and the others. (uncertain)

Tregonning Hill China Clay Pits

Cookworthy discovered china clay at Tregonning Hill in 1746, after seeing miners at the Great Work Mine repair their furnaces with it. (disputed)
Cookworthy observed the fine clay being used to repair furnaces while visiting the area in 1745. (disputed)
Argall took over the Tresowes and Wheal Grey setts in 1875 and retired in 1893. (disputed)
Argall took over Tresowes Hill works in 1886 and the other Tresowes setts in 1889, when he retired and his setts passed mostly to John Lovering and Company. (disputed)

Tregurtha Downs Mine

The BGS mine-plans catalogue holds a Mining Remediation Authority abandonment plan titled 'Tregurtha Downs' (catalogue OMR305, Tin Ore, dated 1891); the catalogue gives no location and the plan's details do not clearly tie it to this working, so it may belong to another of the same name. (uncertain)

Treskerby Mine

A separate account of the wider Gwennap mining district gives Treskerby's total output as around 32,000 tons of copper ore, notably lower than the sum of the two production figures recorded by Mindat for 1815-32 and 1922-27; the discrepancy is not resolved by either source. (disputed)

Tywarnhayle Mine

The Cornwall and Scilly Historic Environment Record describes surviving remains of a 1906 flotation plant -- concrete walls, loadings, a tank and a chimney -- which it calls the remains of 'the world's first commercial froth flotation plant'; no other source corroborates this specific superlative, though multiple sources agree an early Elmore flotation trial took place here in 1906. (disputed)

Ventonwyn Mine

Cornish Mine Images gives 138 tons of tin from the 1903-1907 working. (uncertain)
A 2026 account gives 167 tons of black tin between 1889 and 1909, after which the mine was abandoned, and a shaft about 350 feet deep. (uncertain)

West Crinnis Mine

The earliest workings here were known as Wheal Regent and were later included in the larger West Crinnis sett. Cornwall Calling and mindat both date that to 1855, mindat citing Dines's 1956 memoir; the directory of 1856, a contemporary compilation, still describes Wheal Regent as the sett bounding West Crinnis on the east. (disputed)

Wheal Busy

Sources differ on the date and the machine. Grace's Guide has a Boulton and Watt pumping engine installed late in 1777, the first of its type in Cornwall; other accounts describe Watt rebuilding Smeaton's 72-inch engine of 1775 in 1778. Both agree Wheal Busy was where Watt's engine first worked in the county. (disputed)
Figures differ by phase and are not directly comparable: 27,000 tons of arsenic is given for the mine's life, against 750 tons raised between the 1907 plant opening and closure. (disputed)

Wheal Damsel

Widely repeated figures give Wheal Damsel's working life as 1815-1872 with around 37,000 tons of copper ore produced, and West Wheal Damsel (Wheal Spinster) as worked 1852-1874 for a further 29,150 tons -- both traced to Mindat. (uncertain)

Wheal Ellen

South Wheal Ellen worked from 1845 to 1861, producing 9,000 tons of copper, some lead and some zinc. (disputed)
South Wheal Ellen worked from 1856 to 1861, producing 2,600 tons of copper, some lead and some zinc. (disputed)

Wheal Fortune

Recorded tin output totals 2,992 tons of black tin (2,569 tons 1855-1868, a further 423 tons 1873-1896), plus 322 tons of copper ore; the GCR account describes main lode production as effectively finished by 1896, while another account has tin extraction continuing to 1906 on a reduced scale — the two describe different things, recorded lode output against the site's working life. (disputed)
Documentary evidence suggests mining activity on the site may date to 1508, recorded under early names "Cog-an-bans" or "Goghan Bras"; tin veins from this period, called the Conqueror branches, are still traceable — a 2007 caving-forum discussion of the site independently refers to old, probably 18th-century, exploratory levels at 'The Conqueror' branch. (uncertain)
The mine continued under different companies until 1912, briefly renamed New Great Wheal Fortune in 1908-09; a lone miner is reported to have worked its burrows for wolfram in the 1950s, recovering about two sacks a day. (uncertain)

Wheal Friendly

Cornish Mine Images dates the 60-inch pumping engine house to 1902; Historic England's listing dates it to about the mid to late 19th century. (disputed)
A 2023 photograph appears to show the engine house converted into a modern dwelling. (uncertain)

Wheal Grey Mine

In 1868 some of the mine was incorporated into Great Work Mine, but this section was abandoned in 1873, just before mining ceased there. (disputed)
Wheal Grey was worked for tin and china clay from 1838 to 1910, producing 116 tons of tin in all. (disputed)

Wheal Harmony

A Mining Remediation Authority abandonment plan for the combined workings, titled 'Treleigh Consols New Wheal Harmony Wheal Maria', carries an abandonment date of 1864 — a data point suggesting some further activity or amalgamation during the period most secondary accounts describe simply as dormant between the 1844 closure and the 1872 reopening, though the plan's own record gives no further operational detail. (uncertain)

Wheal Jane

A January 2007 report describes an emergency light still on and a transformer still humming in the main processing building at Wheal Jane several years after closure, alongside catwalks, control panels and floors under one to three inches of red mine water. (uncertain)

Wheal Jenkin

The 70-inch engine erected at Bellingham's shaft in 1886 came from Holman's shaft, South Caradon. (disputed)
The 70-inch engine erected at Bellingham's shaft in 1886 came from Marke Valley. (disputed)

Wheal Langford

It was last worked as New Langford in 1884-90. (disputed)
Trials as New Langford took place in 1884-86. (disputed)

Wheal Luna

It was very likely amalgamated with Polberro, and some of the workings were linked. (uncertain)

Wheal Owles

One account gives the mine's deepest workings as around 190 fathoms. (disputed)
Another account gives a maximum depth of over 200 fathoms (about 1,200 feet). (disputed)
The mine never reopened after the 1893 flooding despite a later attempt to float it as 'Wheal Owles and Boscean United'; ownership of the sett later passed to Geevor Tin Mines plc, though no further extraction is recorded there. (uncertain)

Wheal Prudence

The engine stacks were blown up by the military in 1940 so that enemy aircraft could not use them as markers. (disputed)
The engines' houses were destroyed in 1942 as too prominent a feature on the coast. (disputed)

Wherry Mine

Work stopped in 1798 when an American ship drifted onto the shafthead. (disputed)
By 1789 the bridge was destroyed and work stopped. (disputed)