18ct white gold blue john cushion 051 carat diamond necklace p2667 this elegantpendant boasts a stunning cabochon cushion piece of rare blue john stone that has been sourced directly from treak cliff cavern in castleton the stone is placed within an exquisite 18ct white gold setting and surrounded by glistening 051 carat brilliant cut diamonds giving the piece a sophisticated sparklethe pendant hangs from afluid 18 inch long 18ct white gold chain all our blue john jewellery is designe