Blue john necklace triangular silver p1745rthis simple and stylish necklace boasts an unmissable cabochon triangular shaped piece of rare blue john stone that has been directly sourced from treak cliff cavern in castleton the stone has been placed within an exquisite sterling silver setting that hangs gracefully from a delicate silver chain complete with a classic bolt ring clasp for easy wearrall our blue john jewellery is designed and crafted within our very own workshops in ashbourne der