Sterling Silver Blue John Oval Rope Twist Ring. R011. This elegant ring is part of our Heritage handmade jewellery collection and features a striking oval shaped cabochon of the finest Blue John stone that has been sourced locally from Castleton, Derbyshire. The stone is placed within an exquisite Sterling Silver twisted rope setting and is completed with a split shoulder 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 the natural Blue John stone into these stunning pieces of jewellery. You can find other matching Blue John jewellery and other Blue John rings online and in-store. Dimensions Blue John stone 10 x 8mm.