Sterling Silver Blue John Small Cushion Signet Ring, R191. This classic signet style ring features a hand carved oval Blue John gemstone, sourced directly from Castleton in Derbyshire, which is inlaid into a thick band of solid sterling silver. Because the Blue John is inlaid within the yellow gold this creates a beautiful smooth finish and a brilliant shine. Dimensions: Blue John; 10mm x 8mm, Width of band; 3.5mm. All articles Purchased from C W Sellors are lovingly and securely dispatched with our elegant jewellery packaging. Matching items also available within this collection.