Blue john curved 5 stone silver cufflinks cl493 these stylish cufflinks boast five stunning pieces of cabochon blue john stone that has been directly sourced from treak cliff cavern in castleton the stone is set within a sterling silver base which gracefully curves across your sleeve all our blue john jewellery is designed and crafted within our very own workshops in ashbourne derbyshire where a team of skilled craftsmen turn the raw blue john stone into these sophisticated pieces of jewell