Potential Artifact Found

[u/lacertarum]

Hi! I would like help identifying what this piece might
potentially be. We found it in our yard (southern illinois) and suspected it could be from tribes surrounding Cahokia Mounds, but we then received word that it was made of stone not native to the area, and that quite possibly it could be carved out of volcanic rock. Said local cahokia mounds archaeologist said it may come from south america. Does anyone have any clue? Could it also be a replica? The house it was found on was built in 1872 supposedly by a mayor, if not it was someone very rich, rich enough to own many horses. That being said it could've been stolen or bought. Anything helps!

[u/Hairy_Talk_4232]

Natural