Full intact Ammonite fossil (Aioloceras besairiei), opal flashes-(nacre) rainbow and purple flashesFull intact Ammonite fossil (Aioloceras besairiei), opal flashes (nacre) rainbow and purple flashes this is a polished Aioloceras besairiei from Madagascar (AGE: Cretaceous: Albian). also known as Cleoniceras besairiei. or Ammonite. The iridescent colors you can really see in the video, are due to the nacre (the "mother of pearl layer) of the shell, inner layer of this fossilized creature shell weighing 744 grams this will have imperfections i suggest