Wonderful 631ct split Ammonite fosssil with Ammolite Opal

This big fossil was professionally cut and exhibits a beautiful fibonacci sequence with well defined chambers filled with druzy crystals, while the outer shell displays abundant and vibrant red ammolite opal. This piece has amazing size, measuring approximately 87.2mm x 70.1mm x 15.6mm (when together) and comes with display stands. This piece originated in the Cretaceous era, and is approximately 100 million years old. Sourced from Madagascar.