Blue john rope edged port hole necklace silver p2087rthis simple and stylish nautical themed necklace boasts a round piece of rare blue john stone that has been sourced directly from the derbyshire blue john cavern in castleton the stone is set within an unmissable sterling silver base that is detailed with exquisite twisted rope detailing to complete the porthole design the pendant hangs gracefully from a delicate sterling silver chain complete with a classic bolt ring clasprall our blue j