Blue John Cavern Castleton
📍 Derbyshire, United Kingdom · 53.3500°, -1.8000°
Blue John — banded purple-yellow fluorite mined under Treak Cliff since Romans; only ~500 kg remains yearly, carved into Ashford-in-the-Water's famous bowls.
📍 Derbyshire, United Kingdom · 53.3500°, -1.8000°
Blue John — banded purple-yellow fluorite mined under Treak Cliff since Romans; only ~500 kg remains yearly, carved into Ashford-in-the-Water's famous bowls.