9ct yellow gold blue john toscana side marquise ring r513 this striking ring is part of our toscana collection and features a stunning marquise shaped cabochon of rare blue john stone that has been directly sourced from treak cliff cavern in castleton the stone has been placed within an exquisite 9ct yellow gold setting which complements the blue john beautifully the ring is completed by a classic yellow gold band all our blue john jewellery is designed and crafted within our very own works