Pyritized Ammonite Fossil Focal Bead measures approximately 29x15x10mm 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 the front, 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 name `ammonite` originates from the Greek Ram-horned god called Ammon. 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. The ancient Romans believed a Pyritized ammonite under your pillow would bring prophetic dreams! Imagine owning a natural Ammonite Fossil which has been encased in the Earth`s ancient sea for 400 million years.