18ct white gold 030ct diamond blue john swirl stud earrings e2000 these elegantstud earrings boast two stunning round pieces of rare blue john stone that has been directly sourced from treak cliff cavern in castleton the stone is placed within an exquisite 18ct white gold setting and surrounded by dazzling 030 carat brilliant cut diamonds in an overlapping swirl design creating a breathtaking sparkle all our blue john jewellery is designed and crafted within our very own workshops in ashbo