9ct Yellow Gold Blue John Heart Outline Stud Earrings. E1911. These feminine heart stud earrings are made from 9ct Yellow Gold, and are created using the highest quality, hand carved Blue John. The rounds of Blue John have been sourced directly from the Treak Cliff Cavern in Castleton, Derbyshire. They are secured by a yellow gold post and butterfly fastening. 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 stunning pieces of jewellery. You can find other matching Blue John jewellery and other Blue John earrings on our website. All articles purchased are lovingly and securely dispatched with our elegant jewellery packaging.