9.4" Sphenodiscus Ammonite With Rare Purple Iridescence

This is a gorgeous Sphenodiscus splendens ammonite from the Fox Hills Formation of South Dakota. What makes this specimen so unique is that it has a brilliant purple iridescence on one side. While many ammonites from this area exhibit iridescent reds, and greens, purple is very rarely seen.

This 70 million year old ammonite lived when South Dakota was a shallow inland sea. It was found preserved in a concretion that was split open. It then had to be hand prepared to remove the hard rock surrounding it from the shell, a very time consuming task. The results are superb though and this ammonite would make a truly impressive display.