Product Details

Blue John (also known as Derbyshire Spar) is a semi-precious mineral, a rare form of fluorite with bands of a purple-blue or yellowish colour. In the UK it is found only at Blue John Cavern and Treak Cliff Cavern at Castleton in Derbyshire. During the 19th century, it was mined for its ornamental value, and mining continues on a small scale.

The most common explanation for the name is that it derives from the French bleu-jaune, meaning ‘blue-yellow’. The story goes that Blue John was exported to France where it was used by ormolu workers during the reign of Louis XVI (1774–91). However, there is no archival record of any Blue John being exported to France, and the early ormolu ornaments which use Blue John were being manufactured by Matthew Boulton of Birmingham in the 1760s.

An alternative origin of the name derives from an old miners’ name for the zinc ore sphalerite, which they called “Black Jack”. Thus, the unique blue stone mined in these caverns could easily have become known as “Blue John”.

Very good condition overall, natural inclusions to the stone. Each vase has one minor pin-hole to the back of the bronze mount. Ready to place.