A 2mm hole is drilled on top.  Ammonites are prehistoric nautilus related to the modern day nautilus, squid, and octopus family. Ammonites are called cephalopods because their heads and tentacles protruded out of the same opening; they grew by building larger chambers on their shells. These specimens were found in Majanga, Madagascar, they date back to the Cretaceous period (65 - 146 million years ago).

43mm x 35mm