This internal mold of a gastropod fossil was given to me at a recent local geology meeting. The person who gave it to me said a batch of them was given to him by someone who thought they were from Missouri.
After doing some Internet searching I determined this fossil mostly like resembles the inside mold of a snail shell fossil being sold as a chalcedony or agate snail fossil from Morocco, Africa. I have seen it listed as found in the Atlas Mountains or Assa or Dakla Oued ed Dahab Lagouira in Morocco.
The fossil might date to the Eocene Epoch. It might be a
Turtella or
Cerithium. I thought it might be fluorescent but it did not under long wave ultraviolet light. Thanks to Dale for the fossil.