18ct Yellow Gold Blue John Heritage Round Necklace. P018. This classic necklace is part of our Heritage handmade jewellery collection and features a stunning cabochon of fine Blue John stone which has been sourced directly from Castleton, Derbyshire. The gemstone is simply and exquisitely set in 18ct Yellow Gold. Sold complete with an 18 inch 18ct Yellow Gold chain which fastens securely with a bolt ring style clasp. All our Blue John jewellery is designed and crafted within our very own workshops in Ashbourne, Derbyshire where a team of skilled craftsmen transform natural pieces of Blue John into these stunning pieces of jewellery. You can find other matching Blue John jewellery on our website. All articles purchased from C W Sellors are lovingly and securely dispatched with our elegant jewellery packaging. Dimensions: Blue John: 15mm x 15mm.