Mineral Gallery

Gold, Carnon Stream Works, Perranarworthal, Cornwall, England

Gold is a native element and precious metal which has been prized by mankind for thousands of years for its beauty, malleability and resistance to corrosion. This gold nugget is the largest known to have been found in Cornwall and weighs 1 oz t, 18 dwt. 6 grs. It was found in January 1808 in the Carnon Valley tin-stream works and bought by collector Philip Rashleigh in March of the same year. Rashleigh wrote in his Manuscript (112 Au): 'Native Gold found in Carnon Stream work in Cornwall weighs - 1 oz. 18 pw. 6 gr. Troy this piece has had all the extra matter picked out except a mite in one place the marks of many others remain. The smoothness of the piece shews the great time it has been washed by the water where it was exposed and the hollow parts more rough gives a proof of its not being manufactured'. In the ownership of Mr Wills, a silversmith from Truro, the find was reported in the Royal Cornwall Gazette on 6th February 1808 'this is unquestionably the largest and most beautiful specimen ever found in Cornwall, or probably in any other country'. The paper reported in March 1808 that Rashleigh purchased the specimen from Mr Wills. Mineral analysis undertaken in 2018 indicates that the gold content in the nugget is in the high 90s while other gold nuggets from the Carnon Stream Works, which were analysed, are around the 70s. As a result, it has been suggested that this gold nugget may have been refined and worked into a forgery by the silversmith who sold it to Rashleigh. Rashleigh Collection.

© RIC, photographer A.G. Tindle

Bournonite with Quartz, Herodsfoot Mine, Lanreath, Cornwall, England

Steel-grey twinned bournonite crystals, in distinctive cog wheel formation, with colourless quartz. This fine specimen from the lead and silver mine, Herodsfoot, may have been acquired by the Royal Institution of Cornwall as part of a group of specimens purchased from Richard Talling, the great Cornish mineral dealer, for £8.10s in December 1858. Bournonite, a rare sulphide of copper, lead and antimony, was first described in 1797 by Philip Rashleigh of Menabilly in Cornwall, who included illustrated descriptions of two specimens in his publication Specimens of British Minerals, Selected from the Cabinet of Philip Rashleigh. The specimens described by Rashleigh came from Wheal Boys, an antimony mine in St Endellion parish and the type locality for bournonite.

© RIC, photographer A.G. Tindle

Galena, Earl Ferrers' Mine, Staunton Harold, Leicestershire, England

Reticulated mass of grey galena on top of octahedral crystals of galena with colourless calcite and brassy yellow chalcopyrite, on pink baryte. This specimen is a fine example from the Earl Ferrers' Mines in Staunton Harold. Collector Philip Rashleigh wrote in his mineral catalogue: '167 Crystallised Lead Ore upon Solid Lead Ore and Calcareous Stone of a Redish Colour full of small grains of Copper Pyrites. This comes from Ld. Ferriss Mine, a Lime Work in Leicestershire r.r.r.'. Galena is the primary ore mineral of lead. Rashleigh Collection.

© RIC, photographer Roy Starkey