Silver blue john marcasite twisted spiral edge pendant necklace p2141 this unique necklace boasts a stunning ovalcabochon of the finest blue john stone that has been sourced directly from the treak cliff cavern castleton derbyshire the stone is set within the centre of an exquisite sterling silver pendant that is surrounded by a twisted edge designembellished by dazzling marcasite giving the piece a magical sparkle the pendant hangs gracefully from a fluid 18 inchsilver chain complete