Silver blue john marcasite oval triangle ring r748 this simple and stylish ring boasts an oval shaped cabochon of rare blue john stone in the centre that has been directly sourced from treak cliff cavern in castleton the stone is placed within an exquisite sterling silver setting that showcases triangledetailing embellished by dazzling marcasite stones bringing a sophisticated sparkle to the piece the ring is completed by a classic sterling silver band all our blue john jewellery is desig