18ct White Gold Blue John 0.28ct Diamond Claw Set Necklace Oval. P2998. This exquisite necklace features a stunning oval shaped cabochon of the finest Blue John stone, sourced directly from the Treak Cliff Cavern in Castleton, Derbyshire. The heart shaped 18ct white gold frame is embellished by dazzling 0.28 carats of brilliant cut diamonds. The pendant hangs gracefully from a fluid 18 inch long 18 carat white gold chain complete with a classic bolt ring clasp for easy wear. At C W Sellors, we have an expert team of gemstone and diamond specialists who handpick and grade each jewel to meet our high standards and a team of talented in house designers who combine their talents to bring you our exclusive Precious Gemstone collection. You can find other Blue John pieces online and in store to compliment this necklace. All articles purchased from CW Sellors are lovingly and securely dispatched with our elegant jewellery packaging. Matching items are available within this collection.