Sterling silver blue john pear celtic ring r845 this elegant ring features a cabochon pear shaped hand carved blue john which has been sourced directly from the derbyshire blue john cavern in castleton the highly polished blue john is framed by a unique and beautiful celtic style band of sterling silver 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 into these stylish p