My dad's friend gave this chess set to me. he said he got in mexico in the 90s when he was in the army. the pieces look like easter island heads, 🗿 besides the knights just being a horse, and the bishop having 4 points at the top and kinda like a cyratal thing in the middle. They also have stickers on them which say "ELGIN". they also are made of some kind of rock. if anyone could help me figure out what this is, please tell me. yall can also ask me for any other details on the pieces if you want.