Sterling Silver Blue John Marcasite Pear Beaded Edge Ring. R816. This feminine Sterling Silver, Blue John and Marcasite ring features a teardrop shaped cabochon of Blue John stone, that has been sourced directly from Castleton, Derbyshire. The striking stone is surrounded by glittering Marcasite and framed by a beaded silver design.  All our Blue John jewellery is designed and crafted within our very own workshops in Ashbourne, Derbyshire where a team of skilled craftsmen transform the natural Blue John stone into these stunning pieces of jewellery. You can find other matching Blue John jewellery and other Blue John rings on our website. Silver Blue John Marcasite Pear Beaded Edge Ring