Stunning Opalized Cretaceous Belemnite Fossil

Description: This specimen comes from Coober Pedy in Australia, a region renowned for its opal production. Indeed, Coober Pedy is known as the opal capital of the world. It is the alignment of the hydrated silica spheres which ultimately results in the rainbow effect of precious opal, the result of deflection and diffraction of light as it passes through the planes of hydrated silica molecules. The size of the spheres impacts the colors seen, with smaller spheres resulting in blues and larger spheres in reds. The opalized state of this intact shell is typical of what is found, and is a consequence of the fact that theback part of the shell, known as a guard or rostrum is the part of the organism subject to calcification, much like the Cuttlefish of today. Many types of opalized fossils have been found, from individual dinosaur bones and belemnites, to entire opalized Plesiosaur skeletons valued in excess of a million dollars.