Sterling Silver Blue John Four Stone Small Dragonfly Necklace. P1896. This striking pendant boasts four unmissable tear drop shaped cabochon pieces of rare Blue John stone that has been directly sourced from Treak Cliff Cavern in Castleton. The stone has then been set into an intricately crafted sterling silver dragonfly design that sits gracefully on a elegant 18" sterling silver chain. 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 necklaces on our website.