Sterling silver blue john marcasite oval art deco necklace p2125 this romantic vintage style pendant features a highly polished cabochonof the finest blue johnstone that has been sourced directly from the derbyshire blue john cavern in castleton the stone is set within the centre of a sterling silver pendantembellished with dazzling marcasite stones giving the piece a sophisticated sparkle thependanthangs from an 18 inch longsterling silver chain complete with a classic bolt ring cla