Sterling Silver Blue John Marcasite Ribbon Edge Ring. R817. This feminine ring boasts a stunning round cabochon of rare Blue John stone which has been directly sourced from Castleton, Derbyshire. The stone is placed within an exquisite sterling silver setting with an enchanting overlapping ribbon detailing embellished by dazzling marcasite stones. Completed with a classic sterling silver band. 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: 19mm x 17mm, Blue John; 9mm x 9mm.