Ammonite pyrite replacement, Pleuroceras sp., Jurassic, Buttenheim, Germany
This specimen contains the fossilized remains of a single ammonite. The outer shell material has been replaced by pyrite, which has been polished to further enhance its appearance, contrasting with the matte grey calcareous matrix. This specimen exhibits beautiful detailing of the ridged whorls of the shell. Small irregularities in this surface represent suture patterns or other post-death alterations of the shell.