Blue John, also known as Derbyshire Fluorspar, is a semi-precious mineral known for its purple, blue and yellow colouring. Considered to be Britain’s rarest mineral, the majority of the mines are now extinct, with only a few small veins and nodules of the gemstone remaining.

The name ‘Blue John’ originates from the French term ‘blue et jaune’. This translates to ‘blue and yellow’ reflecting the stone’s distinctive colour. It is a highly valuable gemstone as it contains a variant of Calcium Fluoride which creates a unique crystal structure and gorgeous strikes of colour.

Blue John items

History of Blue John

The Romans discovered the first extracts of Blue John two thousand years ago. When searching for lead ore deposits, three miles from Castleton in the village of Brough, they discovered this semi-precious gemstone out of luck.

Furthermore, during the 19th century and the Regency period Blue John was at its most popular and highly regarded for its unique colour. It was often crafted into vases, tables, columns and windows for houses of the upper class, such as Buckingham Palace and Chatsworth House.

Where is Blue John found?

Generally, it tends to be found in small deposits which line the walls of the caverns or fill the cavities of the pipe veins. Today, out of the three most prolific mines – Blue John Cavern, Old Tor Mine and Treak Cliff Cavern it is only Treak Cliff which mines any gemstone quality material. It is widely believed that Treak Cliff Cavern was also the first mine ever to house the gemstone. The deposits of quality stones are found in veins of about 3 inches in thickness and are most commonly extracted in fist-sized pieces or smaller.

 

Blue John Collectables at Auction

A superb ormolu-mounted Blue John table candelabrum

Lot 24

A superb ormolu-mounted Blue John table candelabrum

Price Realised: £5,742

 

A superb Blue John campana-form urn and cover

Lot 98

A superb Blue John campana-form urn and cover

Price Realised: £25,520

Blue John Jewellery at Auction

Nevertheless, Blue John is still extremely popular highlighted by the lots below.

9ct gold blue john pendant, with chain

Lot 1420

9ct gold Blue John pendant, with chain

Price Realised: £123.50

 

9ct gold blue john fluorite stud earrings

Lot 543

9ct gold Blue John fluorite stud earrings

Price Realised: £182.00

 

9ct gold Blue John bracelet

Lot 657

9ct gold Blue John bracelet

Price Realised: £585.00

Valuations

Our valuations are free, with no obligation to sell with us. Our experts will value your item with an estimate, so you can find out what it could achieve at auction.

The process is simple. You can fill in a form online or book an appointment to visit either of our offices in Birmingham or London. Virtual valuation appointments are also available.

Find what you’re looking for

Make sure you don’t miss finding that special something by signing up to our email alerts. You’ll be the first to know when catalogues become available, receive invitations to special events and preview the hottest lots from our auctions, plus much more.

Finally, why not use our free personal shopping service? Sign up for lot alerts and tell us exactly what you want. Each time we upload a catalogue, we search for your keywords and email you lots matching your interests. Your personalised email will include images, lot descriptions and auction details.