Pyritized Ammonite Fossil Focal Bead measures approximately 18x39x16mm in size, the fossil exhibits a metallic luster which is the result of Pyrite (iron sulfide) forming against the Ammonite structure over millions of years to create a fossilized form, the fossil has spiral formations on both the front, the fossil`s reverse shows a second Ammonite in Quartz measuring approximately 16x14mm, 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. 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.