DERBYSHIRE BLUE JOHN

Discovered almost two thousand years ago by the Romans, Blue John is a rare natural variety of Calcium Fluorite known as radix amethysti, with its highly distinctive and prized coloured veins. The only known deposit of this unusual mineral occurs in the hills to the west of Castleton in the Hope Valley, Derbyshire.

First recorded in the late 17th Century, Blue John, or 'Derbyshire Spar' became increasingly popular in the second half of the 18th Century, fashioned into decorative objects and architectural purposes including chimneypieces. One of the first pioneers of this type of work was Robert Adam, who introduced a Derbyshire spar or 'bluejohn' tablet in the chimneypiece frieze of the neighboring Kedleston Hall's State Bedroom for his patron, Sir Nathaniel Curzon, 5th Bt. (1726-1804).

Today, Blue John is perhaps most celebrated in the work of the Birmingham silversmith and ormolu-manufacturer Matthew Boulton. Boulton wrote to John Whitehurst of Derby in December of 1768 stating that he had 'found a use for Blew John which will consume some quantity of it. I mean that sort which is proper for turning into vases.' In March of the following year Boulton purchased 14 tons cwt of this prized stone from John Platt at Castleton for the then substantial sum of £81 1s. 6d. Undoubtedly, the majority of this stone was destined to be mounted with ormolu in the form of elegant candelabra, urns, candlesticks and perfume burners. However, others no doubt preferred the stone in its purer form - with the richness of its remarkable colouring and the skills of the lapidarist alone coming to the fore.

Blue john vases of the large scale seen in the present lot are remarkable and rare because it is difficult to extract large slabs of the fluorspar from the caverns and mines of Treak Cliff. The deposits, which occur in voids in the Boulder Bed and in ancient caves in the underlying Carboniferous Limestone are usually less than 4 inches (10 cm.) thick although occasionally the linings meet and fuse to create nodules or ‘double stones’ up to 8 inches (20 cm.) (T.D. Ford, ‘Postscript to The Largest Blue John Vases ever made’, Bulletin of the Peak District Mines Historical Society, vol. 11, no. 6, Winter 1992, p. 264).

Boulton was not alone in his use of the Derbyshire mineral and there are records listing several further Derbyshire makers in both the late 18th Century and early 19th Century. These include Robert Bradbury of Castleton, Derbyshire, who supplied six Blue John bodies for sphinx vases for Boulton in 1770, as well as James Shaw and Vallance - both of Matlock - who produced vases of monumental scale.

The mines and seams of Blue John are now largely exhausted.