When your grandparents tell you not to remove something when you’re renovating, we suggest you listen to them. Especially when said thing looks like it could be a portal to an alternate dimension. The OP couldn’t help but wonder what this intricately carved stone object was. Doesn’t it look like something from the German series “Dark?”
According to the internet, this is a mottled jade Aztec Sun Stone. It’s essentially a sculpture dedicated to the sun and it features hieroglyphs of days, months, and of course, the sun. It’s certainly interesting to look at but like we said earlier, we think it’s probably best to leave it alone.