The sale is one of the finest collections of Blue John, a semi-precious mineral found only in two locations in Derbyshire, which has been mined and crafted into precious objects since the eighteenth century. The sale boasts over 250 individual items, making it a major event for Blue John collectors worldwide.

85208-19 A large pair of Blue John obelisks

"Blue John is big news at the moment following the discovery of a major new seam at Treak Cliff in Derbyshire and we are expecting interest from around the world for this one-off auction," said Mark Huddleston, Antique & Fine Art Specialist at Fellows. "The London preview, combined with two additional preview events in Buxton and Ashbourne, will ensure that the collection reaches as many people as possible before the sale in October."

Believed to have been discovered by the Romans more than 2,000 years ago, Derbyshire Blue John became highly fashionable in the 1700s when it was used to create everything from urns to bowls and jewellery. Examples can be found in some of England's great houses, including Chatsworth, and it was most famously used by Robert Adam to create an iconic fireplace in the state apartments at Kedleston Hall.

85208-65 A fine pair of Blue John chalices

The collection to be offered by Fellows features a wide range of objects from small bowls to large neo-classical vases, cups and trinkets estimated at between £30 and £30,000. The highlight of the sale is a late 18th century ormolu-mounted Blue John urn, attributed to Matthew Boulton, featuring a neoclassical shouldered ovoid body, bifurcated foliate scroll handles and a canthus-cast square base.

"There are many legends about Blue John, including the Roman belief that you could not become intoxicated if you drank wine using a chalice made from the mineral," added Mark. "Even the origin of the name is a mystery, although it's commonly believed to have come from the French bleu-jaune, meaning 'blue-yellow', when it was exported to France during the reign of Louis XVI."

85208-159 A magnificent ormolu-mounted Blue John urn

Fellow's having been working with Treak Cliff Cavern, near Castleford in Derbyshire, in order to appreciate the unique properties of the stone. The mine is limited to producing just one tonne per year, with no two items made from Blue John being the same. The incredible softness of the mineral means it is extremely fragile, but can be carved into shapes and delicate jewellery that would be impossible to make from other materials.

Search the full catalogue on Barnebys here.

Viewing will take place from 1st-5th October at Fellows in Birmingham.