Blue john drop marquise silver earrings e1414rthese elegant drop earrings boast a marquise shaped piece of rare blue john stone that has been sourced directly from treak cliff cavern in castleton the stone is set in the centre of a sterling silver mount which hangs gracefully from the lobe with the classic post and butterfly fasteningsrall our blue john jewellery is designed and crafted within our very own workshops in ashbourne derbyshire where a team of skilled craftsmen turn the raw blue