Sterling Silver Blue John Marcasite Beaded Edge Pear Necklace. P2121. This eye-catching pendant features a teardrop shaped cabochon of fine Blue John stone, sourced directly from Castleton, Derbyshire. Derbyshire. Dazzling Marcasite stones embellish the setting and bail, giving the piece a vintage feel. Sold complete with an 18 inch sterling silver chain which fastens with a classic bolt ring style clasp. All our Blue John jewellery is designed and crafted within our very own workshops in Ashbourne, Derbyshire where a team of skilled craftsmen transform natural pieces of Blue John into these stunning pieces of jewellery. You can find other matching Blue John jewellery on our website. All articles purchased from C W Sellors are lovingly and securely dispatched with our elegant jewellery packaging. Dimensions: 26mm x 19mm, Blue John: 15mm x 10mm.