C w sellors necklace blue john and marcasite p2144 this stunning necklace boasts an unmissable cabochon oval shaped piece of rare blue john stone in the centre that has been sourced directly from the derbyshire blue john cavern in castleton the stone is placed within an exquisite sterling silver diamond setting that showcases dazzling marcasite giving the piece a sophisticated sparkle a second silver diamond crowns the pendant as it hangs gracefully from the delicate silver chain complete w