Blue John Ring Oval Stone Large Silver. R013. This striking statement ring, part of our Heritage handmade jewellery collection boasts an unmissable cabochon oval shaped piece of rare Blue John stone that has been sourced directly from Treak Cliff Cavern in Castleton. The stone is framed within an exquisite Sterling Silver setting and completed with a wide Sterling Silver band. All our Blue John jewellery is designed and crafted within our very own workshops in Ashbourne, Derbyshire where a team of skilled craftsmen turn the raw Blue John stone into these stunning pieces of jewellery. You can find other matching Blue John jewellery and other Blue John rings online and instore. Blue John and Sterling Silver ring.