Sterling silver blue john seven marquise stone celtic bracelet b594 this elegant bracelet features seven beautiful hand carved marquise shaped blue johngemstones that has been sourced directly from the derbyshire blue john cavern in castleton the highly polished blue johngemstones are framed within a unique sterling silver celtic design which fastens securely with a classic lobster clasp for easy wear all our blue john jewellery is designed and crafted within our very own workshops in as