Blue john silver 8mm stud earrings e1345 these simple and stylish stud earrings boast two round pieces of rare blue john stone that has been sourced directly from treak cliff cavern in castleton the stones are set on exquisite sterling silver and fastened by classic post and butterfly fastenings for easy wear 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 stun