9ct Yellow Gold Blue John Rhombus Necklace. P084. This elegant, contemporary necklace features a hand carved cabochon of the finest Blue John stone, sourced directly from Castleton, Derbyshire. The gemstone is polished to perfection for a smooth finish. Sold complete with an 18 inch 9ct yellow gold chain which fastens with a classic 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 stylish 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: 21mm x 19mm, Blue John 16mm x 16mm.