Blue john marquise 9ct yellow gold necklace p388rthis simple and stylish necklace boasts an unmissable cabochon tear drop shaped piece of rare blue john stone that has been sourced directly from treak cliff cavern in castleton the stone is set within 9ct yellow gold and hangs gracefully from a matching yellow gold chain complete with a classic bolt ring clasprall our blue john jewellery is designed and crafted within our very own workshops in ashbourne derbyshire where a team of skilled craf