Antique Marius Hammer sterling silver enamel butterfly brooch

A rare antique solid silver medium sized butterfly brooch from the most collectible of all the enamelists in an unusual colour way with black body and delicate yellow and pink wings with some black veining, natural guilloche pattern with a c type clasp to the pin at the back and an overall gilt wash - marked for Marius Hammer of Bergen - total weight 16.4grms - overall dimensions 62 x 36mm - c.1920 Norway