Blue john necklace oval locket marcasite silver p2146rthis exquisite locket boasts an unmissable cabochon oval shaped piece of rare blue john stone that has been sourced directly from treak cliff cavern in castleton the stone has been placed within the centre of an intricate open detailed sterling silver oval design embellished by glistening marcasite stones giving an elegant and sparkly finish to the piece the locket hangs gracefully from a matching sterling silver chain completed by a cla