Ammonites are extinct shelled marine animals that are related to octopus and squid. This Placenticeras meeki specimen lived in the late Cretaceous, about 71 million years ago. This specimen's iridescent red, blue, orange, and green colors are caused by the reflection of light from the layers of aragonite that compose the shell of this ammonite. Because of its similarity to opal, such ammonite shells are mined, cut, and polished under the gemstone name of "ammolite." This specimen comes from Albe