Wheal Brothers (Wheal Duchy), East Cornwall Silver Mines (St Vincent Great Consols; incl. Wheal Emily; Wheal Georgiana; Wheal Mercer), Wheal Langford (New Wheal Langford; Baring and Langford Mine), Calstock, Cornwall, England, UKi

Regional Level Types
Wheal Brothers (Wheal Duchy)	Mine (Abandoned)
East Cornwall Silver Mines (St Vincent Great Consols; incl. Wheal Emily; Wheal Georgiana; Wheal Mercer)	Group of Mines
Wheal Langford (New Wheal Langford; Baring and Langford Mine)	Mine (Abandoned)
Calstock	Civil Parish
Cornwall	County
England	Constituent Country
UK	Country

Wheal Sisters was developed on the same lode to the east.
The mine was first opened about 1810 under the name of Wheal Duchy. When prospecting for copper ore, silver ore was found probable associated with a north-south crosscourse. The lode is recorded as being up to 31 cm wide, and the silver ore up to 15 cm wide. The silver lode was found in the adit level, from there it extended to a depth of 55 m, and for a length in the lode of 5.5 m. The silver deposit consisted of native silver, pyrargyrite, acanthite, galena, siderite. (Also recorded are grey and black sulphides of silver and antimony, without stating what they where).

Wheal Duchy was closed in 1816, but was reopened in 1833, and called Wheal Brothers. When the 30 fathom level was investigated a quantity of silver ore was found standing in the stopes. The previous owners had apparently not recognised it as silver ore. And within three months nearly 6000 uk pounds worth of silver ore had been produced. In 1874 the mine was being worked inconjuction with Silver Vally mine (which was at work in 1852 as well).
Recorded production:
Wheal Duchy: 200 tons of silver ore

September 2024. Beside the stile at the end of the footpath from Harrowbarrow is the almost demolished 1/2 round base of what was presumably a chimney. About 5 m away is another chimney about 3 m / 10 feet tall. A little off to one side of this is a small ruin with a fireplace and another, larger, which is only a few walls.

The site is bisected by a stream that passes into a tunnel that emerges into a deep pit and then flows on into a wheel pit. I believe the pit is not a shaft as it might first appear to be but is simply where the tunnel has collapsed and the ground above has subsided and been washed away. The tailrace of the wheelpit takes the water a short distance through a narrow channel but then the stream disappears underground again.
Beside the stream is an area comprised of soft, red, sand.
On the western side of the stream the hillside has been extensively excavated into numerous pits and there appear to be several flues and possibly several leats / launders. Almost at the top of the hill stands what appears to be an arsenic stack, though it has apparently been built in a deep depression in the ground that has been excavated into surrounding banks. Where a part of this has been recently dug away several alternating layers would tend to suggest this is spoil from a shaft.

Geochronology

Geologic Time				Rocks, Minerals and Events
Phanerozoic
	Paleozoic
		Permian
			Guadalupian	ⓘ Major polymetallic mineralization ~270 Ma Cornwall, England, UK
			Cisuralian	ⓘ Porphyry dikes intruded (latest age) ~275 Ma Cornwall, England, UK ⓘ Greisenization (latest age) ~280 Ma Cornwall, England, UK ⓘ Porphyry dikes intruded (earliest age) ~280 Ma Cornwall, England, UK ⓘ Formation of metallized pegmatites ~285 Ma Cornwall, England, UK ⓘ Greisenization (earliest age) ~285 Ma Cornwall, England, UK ⓘ Emplacement of major plutons ~295 Ma Cornwall, England, UK

Other Regions, Features and Areas containing this locality

References