9ct yellow gold blue john round swirl stud earrings e1625 this dainty pair of earrings have been created using the finest quality hand carved blue john which is sourced directly from the treak cliff cavern in castleton derbyshire the circular blue john gemstone is surrounded by a swirl design of 9ct yellow gold the earrings are completed by post and butterfly fasteners for easy and secure wear all our blue johnjewellery is designed and crafted within our very own workshops in derbyshire