9ct yellow gold blue john toscana marquise twist ring r512 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 which twists with design of the setting there are matching items within the