It’s was a rainy morning in Castleton, after eating some yummy pastries we arrived at 10pm for the first Treak cavern tour. This my third visit to this cave; the other times I visited once long ago with my family and more recently unaccompanied. Our well mannered guide was an humorous chap with a lot of information to share with us. The detailed tour was worth the money although I did notice there was at present no ‘cafe’ functioning at the cavern; at busy times there is a wait so a cup of tea is most called for; especially in dull weather!
I’m no geologist but I found it remarkable that some people believe blue John to be an amethyst, it’s a fluorite!
Around the hills of Castleton is said to be the only place where Blue John is found in the whole wide world although I have heard rumour that the Fluorite has also found in Northern Scotland. Due to large quantities being exported to France the name is derived from French words (bleu jaune) which literately translates as ‘blue yellow’; meanwhile back in England bleu became blue and jaune became John henceforth Blue John.
The cavern was originally explored for lead but to this day none has been found to make any worthwhile profit from extraction.
The value of this fluorite seems to have increased significantly since my last visit, a Blue John silver mounted pendant will cost from £30, £60 up to £150 pounds and mounted on gold more. Bowls start from £600 upwards from memory but noticeable those on display inside the cavern shop were not for sale.
Whilst critical of mining practices there is attached around the story of blue John a fascinating story of the process of creation, invaluable for any child and adult alike.
A visit to Treak cavern is highly recommended should you find yourself in Castleton, Derbyshire.