Blue john barrel silver stud earrings e280rthese sophisticated stud earrings boast two stunning rectangular shaped pieces of rare blue john stone that has been directly sourced from treak cliff cavern in castleton the stone is set within exquisite sterling silver and fastened by classic post and butterfly fastenings for easy wearrall 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