Definition of Blue John in English:

Blue John


  • [mass noun] A blue or purple banded variety of fluorite found in Derbyshire.

    • ‘The name Blue John very likely was made up by John Kirk and Joseph Hall who worked the mines in the 18th Century.’
    • ‘It is likely that they were searching for deposits of lead ore and struck upon an outcrop of Blue John by chance.’
    • ‘Many of our Blue John items can also be made in other stones like Jade, Turquoise or Mother of Pearl.’
    • ‘It looks like at some point the slag from the mine was dumped into this hole in small quantities, and as a boy I found many chunks of Blue John down there.’
    • ‘And please note: because of the nature of Blue John we cannot guarantee that the patterning in the stone you receive will be exactly the same as that shown in the photograph above.’