Art Nouveau Style Round Amethyst Onyx & Marcasite Insect Brooch in 925 Sterling SilverAbout This Item A wonderful sterling silver butterfly design brooch featuring a large cabochon cut black onyx gemstone as and a round faceted amethyst gemstone, finished with two round emerald gemstone eyes. This brooch fastens with a standard brooch pin Gemstone Information Amethyst gets its name from the Greek 'amethustos', which translates into 'to not become drunk' Onyx was worn by Roman soldiers in the belief it would instil them with bravery.