Pyritized Ammonite Fossil Focal Bead measures approximately 38x32x8mm in size, the fossil exhibits a metallic luster which is the result of Pyrite (iron sulfide) entering Ammonite skeleton structure over millions of years to create a fossilized form, the fossil has spiral formations on both the front and the back, the focal bead has been drilled as shown in the enlarged photograph, this Pyritized Ammonite Fossil is a stunning metallic fossil with detailed patterning of ridges and spirals, and the fossil focal bead shows Pyritized drusy in chamber interiors. The name `ammonite` originates from the Greek Ram-horned god called Ammon. The ancient Romans believed a Pyritized ammonite under your pillow would bring prophetic dreams! Ammonite first appeared in the late Silurian to early Devonian Periods (~400 million years ago) in marine environments, and their demise coincided with the extinction event that closed the Cretaceous Period. Imagine owning a natural Ammonite Fossil which has been encased in Earth`s ancient sea for 400 million years.