Silver Blue John Marcasite Four Arc Round Pendant Necklace. P2140. This Blue John and Sterling Silver pendant features a hand carved round Blue John gemstone set within a detailed floral frame, accented with sparkling Marcasite gemstones.This intricate piece is a perfect gift for yourself or a loved one. It is supplied complete with an 18" sterling silver chain. 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 Marcasite Four Arc Round Pendant Necklace