18ct Yellow Gold Blue John Love Letters Initial Z Necklace, P3473. From the new \'Love Letters\' collection designed and handcrafted by C W Sellors, this 18ct yellow gold necklace features an initial \'Z\' with a circular Blue John stone, sourced directly from Castleton, Derbyshire. The pendant and stone hang elegantly from a 18 inch 18ct yellow gold chain. All our Blue John jewellery is designed and crafted within our very own workshops in Ashbourne, Derbyshire where a team of skilled craftsmen transform the natural Blue John stone into these stunning pieces of jewellery. You can find other matching Blue John jewellery online. All articles purchased from C W Sellors are lovingly and securely dispatched with our elegant jewellery packaging.