A Blue John and gilt-bronze casket 19th century

in the manner of Matthew Boulton, with a swing handle, the raised sloping lid and sides with a guilloche ornament and with inset bevel-edged panels of veined blue john, on flattened bun feet

This is a casket of exceptional quality and colour. To be recommnended.
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

Blue john was a fashionable material used in England during the late 18th and early 19th century for a variety of ornamental wares such as vases, goblets, obelisks columns and tazze.  It is rare to find a casket of this form using the material. Examples of these other objects are discussed and illustrated in Margaret Jourdain, Blue John, Apollo Magazine March 1946, pp.58- 60, Bernard G. Hughes, Derbyshire Blue John, Country Life, 3rd December 1953, pp.1834-1839 and Trevor D. Ford, Derbyshire Blue John, 2000.

Blue john is found almost exclusively at Treak Cliff Castleton, Derbyshire where it has been mined for three centuries. Different parts of Treak Cliff render distinct patterns or veins, formed from the linings of ancient caves of the fillings around boulders. The present panels seem to be what is known as `New Dining Room Vein'. This vein is characterised by a thick white band at the top containing a thin 1mm blue band, a group of dark blue bands close together in the middle and a narrow whitish band towards the bottom. This vein takes its name from a large cavern known as Lord Mulgrave`s Dining Room. Old and New Dining Room veins occur close together off Lord Mulgrave`s dining room.   

 Blue john was and remains highly prized and objects made from the material tend to be of the finest quality.  Examples of blue john can also be found in other major collections including the British Royal Collection , see Jane Roberts, George III and Queen Charlotte, Patronage, Collecting and Court Taste, 2004, pp. 269-278.