Not to be confused with Bluejohn Canyon.
| Blue John Cavern | |
|---|---|
 Blue John seams in the cavern | |
| Location | Castleton, Derbyshire, England |
| Coordinates | 53°20′44″N 1°48′13″W / 53.3456°N 1.8035°W / 53.3456; -1.8035 |
| Geology | Blue John |
| Entrances | 1 |
The Blue John Cavern is one of the four show caves in Castleton, Derbyshire, England. The others are Peak Cavern, Treak Cliff Cavern and Speedwell Cavern.
Description
The cavern takes its name from the semi-precious mineral Blue John, which is still mined in small amounts outside the tourist season and made locally into jewellery. The deposit itself is about 250 million years old.
The miners who work the remaining seams are also the guides for underground public tours. The eight working seams are known as Twelve Vein, Old Dining Room, Bull Beef, New Dining Room, Five Vein, Organ Room, New Cavern and Landscape.
In 1865, Blue John Cavern was the site of the first use of magnesium to light a photograph underground. It was taken by Manchester photographer Alfred Brothers.
Blue John
Main article: Blue John (mineral)In the UK Blue John, or "Derbyshire Spar", is found only in Blue John Cavern and the nearby Treak Cliff Cavern. It is a type of banded fluorite. The most common explanation for the name is that it derives from the French bleu-jaune, meaning 'blue-yellow', but other derivations have been suggested.
References
- "Blue John Cavern". castleton.co.uk. Peak Hideaways. Archived from the original on 21 January 2017. Retrieved 22 January 2017.
- Howes, Chris (23 December 1989). "Art of Darkness". New Scientist. Retrieved 5 July 2014.
- George, Ken (2009). An Gerlyver Meur: Cornish–English, English–Cornish Dictionary. Cornish Language Board. ISBN 978-1-902917-84-9.
