Silver Blue John Marcasite Beaded Edge Pear Pendant Necklace. P2121. This feminine pendant features a teardrop shaped cabochon of rare Blue John stone, sourced directly from the Treak Cliff Cavern in Castleton. The stone is framed by and exquisite sterling silver setting that showcases dazzling marcasite, giving the piece a sophisticated sparkle. The pendant hangs gracefully from a fluid 18 inch long silver chain complete with a classic bolt ring 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 Marcasite Beaded Edge Pear Pendant Necklace. Sterling silver chain 18 inches long, Pendant 26x19mm, stone 15x10mm.