Silver blue john marcasite marquise ringr746 this stunning ring boasts a marquiseshaped cabochon of blue john stone that has been sourced directly from treak cliff cavern castleton the stone is placed within an exquisite sterling silver setting embellished by dazzling marcasite stones bringing a sophisticated sparkle to the piece the ring is completed by a classic sterling silver band all our blue john jewellery is designed and crafted within our very own workshops in ashbourne derbysh