Sterling Silver Blue John Marcasite House Style Butterfly Brooch. M325. Complementing our sterling silver and enamel designs, the introduction of sparkling and natural marcasite stones provides a classic and elegant way to accessorise any outfit.  With a certain Art Deco feel, accompanied by Derbyshire Blue John and Garnets, the collection features wonderful insect earrings, brooches, rings and pendants. This eye catching butterfly brooch is handmade in sterling silver and features four beautifully hand carved Blue John gemstones, sourced directly from Castleton, Derbyshire, which are surrounded by a silver frame accented with sparkling Marcasite gemstones.  Dimensions: 32x45mm.