Sterling Silver Blue John Oblong Signet Ring, R181. This classic signet ring features a hand carved rectangular Blue John gemstone , sourced directly from Castleton in Derbyshire, which is inlaid into a thick band of sterling silver. Because the Blue John is inlaid within the silver, this creates a beautiful smooth finish and creates a brilliant shine.   All articles purchased from C W Sellors are lovingly and securely dispatched with our elegant jewellery packaging. Matching items also available within this collection. Face of ring; 13mm x 12mm, Width of band: 12mm either side of the stone, tapering to 4mm at the back.