Blue John

The name 'blue john' probably originates from the French, words 'bleu-jaune', meaning 'blue-yellow'. "Blue John" or "Derbyshire Spar" is mined Castleton, Derbyshire, England.

Treak Cliff Cavern is one of only two working Blue John mines in the world and extracts approximately half a ton of blue john per year, mostly to be used in jewellery.

Blue fluorite occurs widely throughout Derbyshire and especially in the Ashover and Crich areas.

Blue-banded fluorite is very rare. An ornamental mineral known to the Romans as murrhine may have been a fluorspar similar to Blue John. Recently discovered deposits in China have produced fluorite with colouring and banding similar to the classic Blue John stone.

World Fossils also offers some exellect specimens of gem-quality blue john as well as beautiful Blue John pendants that make ideal gifts.

Visit the shop in Bristol and browse a wide selection of  fossils, gems, crystals and jewellery, as well as some unique specialty items.