The Great Work group of mines are reported to be very old and very rich. The tin mine was recorded to be in production during the 16th Century, employing about 300.
Great Work mine is only a mile north-east of another prosperous tin mine called Wheal Vor. J. H. Trounson in his book “The Cornish Mineral Industry 1937-1951” makes the observation that: “A well known though very peculiar fact in connexion with the mines of this area is that the riches of Wheal Vor were almost entirely confined to the killas, the lodes becoming very poor in the granite, whereas in Great Work precisely the opposite state of affairs prevailed and lodes that had been exceedingly rich in granite were found to practically valueless in the killas. ”
It was stated by Cornish Mining World Heritage Site Bid at http://www.cornish-mining.org.uk/sites/tregon.htm that: “Great Work was the site, in 1689 of the introduction of blasting to mining by Thomas Epsley” but J. H. Trounson once again in “The Cornish Mineral Industry 1937-1951”, disputes this as he states that: “it was either at Wheal Vor or the neighbouring Godolphin mine that gunpowder was first used for blasting”. Whichever account is right it is certain that it was this area that was responsible for the use of explosives in mines.
The clays of nearby Tregonning Hill were used by the miners of Great Work to repair their furnaces and in 1746 a Mr. Cookworth came to stay with Captain Nancarrow of Great Work and saw the miners using this clay. Cookworth took samples back to Plymouth and the clay was used to make porcelain until a source pf purer clay was discovered near St. Austell.
Great Work has an unusual chimney stack as its upper brickwork is in two stages and like many Cornish mines its fortune depended on the price of tin resulting in closure and then reopening. The last reworking was in 1930 when the engine house which formerly held a 60 in pumping engine was cut down and provided with a flat roof.
Today all that remains of this once great mine are the ruins of the pumping engine house and the stack of Leeds shaft. Theses two remains make a distinctive landmark in the dip between Tregonning and Godolphin hills. The property is now maintained by the National Trust and the area is kept clean and free from fly-tipping.