Silver Blue John Three Point Cross Marcasite Necklace. P2115. This sophisticated necklace boasts a stunning round cabochon of Blue John stone that has been sourced directly from Treak Cliff Cavern in Castleton. The stone is set in the centre of this enchanting sterling silver cross which has been embellished with glistening marcasite for an eye catching finish. The pendant sits on a delicate sterling silver chain and is completed by a classic lobster clasp. 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 stunning pieces of jewellery. You can find other matching Blue John jewellery and other Blue John necklaces on our website. Silver Blue John Three Point Cross Marcasite Necklace. Pendant 45x24mm.