Blue john diamond 9ct yellow gold necklace p992c this stunning and sophisticated necklace boasts an unmissable cabochon cushion shaped piece of rare blue john stone that has been sourced directly from treak cliff cavern in castleton the stone is placed within an exquisite 9ct yellow gold setting and crowned by an enchanting 010ct diamond set on the bail the pendant hangs gracefully off a matching delicate 9ct yellow gold chain completed with a classic lobster clasp for easy wear all our bl