Sterling silver blue john round cross design necklace p1853 this exquisite necklace boasts a stunning cabochon round piece of rare blue john stone that has been sourced directly from the derbyshire blue john cavern in castleton the stone is embraced within an enchanting sterling silver cross design with diamond open detailing the pendant hangs gracefully from a matching sterling silver chain complete with a classic bolt ring clasp for easy wear all our blue john jewellery is designed and cr