Gannel 1839 Smelting Works, Newquay, Cornwall, SW 79106113


By Sheila Harper, with additional observations by Melissa Banthorpe, Maria Justamond, Richard Bell and Martin Stolworthy on material from their collections.

Information about this small Smelting Works is very sketchy.

Mining operations around the Gannel are known to have occurred during the 19th century. Lead was the main ore extracted. Chiverton Wheal Rose was situated close to the north bank of the Gannel, near Trethellen Farm. The mine had an engine house and stack and the water was discharged via an adit that opened up onto the beach. In 1863 the mine reopened. The adit was cleared for 120 fathoms on a north-south lode and was crossed by a number of east-west lodes, none more than 2’ wide. The discoveries led to the erection of a 50” cylinder engine and 20 fathoms of pit work. The boiler and parts were brought to the mine in early 1864, but the company was by then in economic troubles, and was wound up in the Stannary Court that year.
There is a record under the name of Rose and Chiverton that gives 40tons of 75% lead ore and 30ozs of silver in 1870 (Collins 1912, 569; Dines 1956, 438. The lead from the mine was taken initially to be smelted, on the southern shore of the Gannel, but as time went by, it became more economical to export the ore to South Wales.

Not much more is know of the smelter other than the extract below.


Site - Crantock Tithe Map 1839 – 600yards N. of Crantock Church, Cornwall

Quote from ‘Old Cornwall’ by S. Teague, Husband

‘ On the Crantock side of the Gannel, between Penpol Point and the road leading from Crantock down to the beach, lead was smelted. The Smelting house stood nearly at the top of the hill and from it ran two diverging trench’s to the beach’.

These trenches are still evident. The lead ore came mainly from the Penhale district. Silver was separated from this lead, and I have heard of a very large plate of silver being lodged in the Albion Inn at Crantock, for the night before being sent on to London.

The smelters name was John Steward. His cottage adjoined the smelting house. I have heard my mother say that in one of her walks to Crantock she had tea at the cottage with Mrs, Steward’

At the Northern extremity of Perran beach, may be seen the cavernous excavations of the Great Perran Iron Lode which crops out here in the cliff, the ‘vein’ wrote John Woodward 1688 – 1728, has been worked formerly and is vastly large. (Natural History of Fossils of England)

From Gravel Hill Mine, which stands above the outcrop, the lode has been traced inland for a distance of three and a half miles, and has been worked in many mines along its course.

During the 1860’s the ore was drawn up the cliff from the seaward side of the workings of Gravel Hill by a 11 ½ inch ‘Puffer’ engine, whence it was carted a distance of three miles to a newly constructed quay on the Gannel for shipment.

Ref. Hamilton-Jenkin - Mines and Miners or Cornwall Vii, Perranporth to Newquay. Mining Journal 31st March to 8th December 1860

Hamilton Jenkin, writing in his ‘Perranporth to Newquay’ on p20 says
‘During this work the lead ore of Penhale Mines (about 1850s) had been carried to a smelting works on the south bank of the Gannel, near Newquay. The site of the establishment is shown on the Crantock Tithe Map (1839) 600 yards North of the Church. The furnace house lay near to the waters edge and was connected by two underground flues to a stack on the hill above’.





Minerals

Slag from the smelter found its way onto the beach below the cliff, where the smelting house was situated. The extent of the slag, in the estuary sand, appears to be from below the base of an adit or flue, found in the cliff, noticeable when walking along the sands from the Beach Road, National Trust car park, Crantock, inland up the Gannel Estuary.

Nearly opposite the Fern Pit Ferry house, there is another adit or flue which one passes. The slag seems to peter out at the point where the cliff turns inland and a beach appears. Here the access up the cliff is much lower than above the smelter. The slag extends at least a third across the Gannel. The amount showing depends upon the depth of the sand. Broken brick, some pale yellow and possibly produced in the area, is also found.

Hamilton-Jenkin produced a map of the area which, should be consulted

The slag varies in size from small pieces to large lumps the size of a bag of sugar.

Mineralization occurs in the vesicles in the slag.

There are a number of different types of slag:
1 Frothy
2 Dense Brown
3 Dense Black

The Frothy material is made up of a very light slag with many cavities like a honeycomb. Crystallisation is very limited in this matrix.

The dense Black slag is almost like a glass or Obsidian and normally without minerals.

The main formation of the crystals has taken place in surface or near surface cavities in the dense Brown slag. Sometimes crystals have formed on the areas that have been exposed to the sea and the elements.

The slag itself has cooled to form crystals, possibly Iron Silicates.

So far minerals found from the result of smelting are lead chlorides, lead-copper chlorides, due to the action of the seawater on the slag. Some lead carbonate is present. Selenite is also present. This is common.

There are parallels with the minerals found at the ancient slag site of Laurium, Greece.





Minerals noted so far:

Cerussite
Lead carbonate, orthorhombic. Forms white or clear elongated or platy crystals in sprays, single, branching etc and ‘dart flight’ twins. Crystals are sometimes striated.

Cumengeite (also spelt Cumengite)
Hydrated lead copper chloride. It is tetragonal and hemimorphic. Colour, is indigo blue.

Laurionite PbCl (OH), orthorhombic and diamorphous with Paralaurionite
Paralaurionite PbCl (OH) monoclinic.
Appears as clear slender lathes ending in a right angle shape (house roof) or blunt ended with corner missing etc.,
Note: Selenite bends, laurionite does not!

Phosgenite
Lead carbonate chloride, tetragonal.
Appears, as clear very lustrous striated, or clear elongated or squat crystals with four or eight sides.

Selenite (Gypsum)
Hydrated calcium sulphate, lathe like, clear crystals, broad or slender terminating in an off set roof shape. Sometimes striated. Fish tail twins. Could be confused with Paralaurionite.

Minerals possibly present:
Boleite
Lead copper silver chloride, indigo blue cubes. Can be associated with Cumengite and Psuedoboleite.


Diaboleite
Hydrated lead copper chloride. Tetragonal but flat and platy, possibly sky blue (also described as cubes with a pyramid on one face.

Psuedoboleite
Hydrated lead copper chloride, Psuedocubes, indigo blue, also described as green plates

Penfieldite
Hydrated lead copper chloride, hexagonal clear crystals, probably elongated. Occurring as single crystals

Galena

Lead sulphide

Lead

Tetrahedrite
Copper iron antimony sulphide

Fayalite and minerals of the Melilite group and Olivine types
These are Iron silicates

Fayalite
Iron silicate. Orthorhombic, thick, tabular, often with wedge shaped terminations. Greenish yellow, yellowish brown, brown. Vitreous to greasy. Clear streak.

Melilite group
All tetragonal, silicates that do not contain iron
Akermanite, Gehlenite, Hardystonite.

Atacamite/Botallackite/Paratacamite
Copper chloride, green crystals
Tallingite – hydrated copper chloride

Percylite
Lead copper chloride – isometric sky blue cubes

Chloroxiphite
Hydrated lead copper chloride, tabular dull olive or pistachio green, bladed sub parallel groupings associated with mendipite. Streak pale yellowish green
Matlockite
Lead chloride. Tetragonal. Tabular/stout pyramidal with small prism faces. Rosettes and aggregates. Adamantine. Colourless, yellowish brown, greenish.

Mendipite
Lead chloride, orthorhombic. Fibrous masses, radiating, colourless, white to grey, often with a yellowish, reddish or bluish tint.

Fiedlerite
Lead chloride, monoclinic. Crystals small, lathe like, tabular, long, twinning common.
Occurs associated with laurionite, Paralaurionite and Penfieldite etc., as at Laurium in Greece

Anglesite
Lead sulphate, adamantine, platy, broad, striated. Sometimes clear.

Mattheddleite
Lead sulphate chloride silicate. Hexagonal associated with Caledonite and Leadhillite
(See Minerals of the English Lake District)

Minium
Lead oxide. Tetragonal. Earthy, massive or powdery. Scarlet red to brownish red, opaque, dull to somewhat greasy. Streak, orange yellow.

Plattnerite ?
Lead oxide.
Black, acicular needles, in a black vitreous slag.  (Martin Stolworthy. April 2008)

Feroxyhyte. ?
Iron hydroxide.
Small browny-red cauliflower like patch’s on Ferrihydrite. Laurion Book pg 125 (Martin Stolworthy. April 2008)

Ferrihydrite.
Iron hydroxide.
Brown hexagonal plates on rusty slag. . Laurion Book pg 125 (Martin Stolworthy. April 2008)


Elyite
Lead Copper sulphate
Very Small mauve needles (Maria Justamond. March 2008)


Richard Bells list of minerals found:

Cumengeite, Diaboleite, Connellite, Cuprite, Anglesite, Phosgenite, Selenite, Fayalite, Cerussite, Cotunnite, Sulphur, Lanarkite, Penfieldite, Aragonite, Laurionite/Paralaurionite, Brochantite, Galena,
Possibles  -  Aragonite, Matlockite, Paratacamite


Melissa Banthorpes list of minerals found:

I have now had a chance to go through my more interesting stuff from the Gannel - basically the blue and green things. I have found the white and colourless material - apart from Phosgenite (of which there is lots and of varying crystal shapes) - difficult to identify and could do with some help with these at some point. I do have Cerussite twins, Selenite, Anglesite, and material that looks like Aragonite and Creedite.

What I appear to have apart form the above - and none of it has been confirmed by analysis - is:

Skeletal crystals/hoppers of Galena

Cumengite/Cumengiete like the illustrations in the Laurion book

Diaboleite like plates 20a, 20b pg 79, and plate 20f pg 83 of the Laurion book

Plates of Pseudoboleite on a Boleite cube which are slightly raised above the cube
Plates of Pseudoboleite as 'cross-shapes' as illustrated on plate 36c pg 117 of the Laurion book

Cuprite as octahedral crystals - I have one good piece

Possibles
Green botryoidal material that could be from the Paratacamite group; some yellow resinous/lustrous discs that look very much like the Perite plate 35 on pg 115 of the Laurion book; and material that looks like Ktenasite (plate 72 pg 165), Mammothite (plates 77a and 77b pg 167), and Beudantite.

Other issues
I have some greenish looking cubes - could these be Boleite?
I have blue and green platy material, and blue and green felty material, which I cannot identify because there are too many options
I also have bits that look like small crystals of Magnetite.


































There is a possibility that more species will turn up as work progresses on the material from this locality.

Martin Stolworthy
April 2008



note this article first appeared in the BMS Newsletter 79, March 2010