18ct white gold blue john rectangle 030 carat diamond necklace sh1 16 this stunning sophisticated pendant boasts an impressive faceted rectangular piece of rare blue john stone that has been sourced directly from treak cliff cavern in castleton the stone has been claw set within 18ct white gold and crowned by three diamonds totaling 030 caratfor an eye catching finish the pendant hangs from afluid 18 inch long 18ct white gold chain all our blue john jewellery is designed and crafted wi