18ct white gold 017ct diamond blue john round stud earrings e1998 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 017 carat brilliant cut diamonds creating a breathtaking sparkle all our blue john jewellery is designed and crafted within our very own workshops in ashbourne derbyshire where a team o