18ct white gold blue john oval 023 carat diamonds stud earrings e1999 these elegantstud earrings boast two stunning oval shaped pieces of rare blue john stone that has been directly sourced from treak cliff cavern in castleton the stone is setwithin an exquisite 18ct white gold setting and surrounded by dazzling 023 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