Silver blue johnmarcasite round ring r747 this petite femininesterling silver blue johnand marcasite ringfeatures a circular central piece of blue johnthat has been sourced directly from treak cliff cavern in castleton the striking stone issurrounded by sparklingpieces of marcasite and set on a classic silver band all 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 john stone