system
A chat on subreddit /r/NoStupidQuestions
human
There's cases of animals eating stones and not being able to pass them resulting in death or surgery.

So it would depend on how big.
gpt
This. A long time ago I had a Great Dane who was into eating rocks. They were volcanic rocks in our backyard, so he was able to chew them enough to be able to swallow them. They blocked up his intestines and could have resulted in a bowel perforation had we not noticed his unusual drooling and got him into an animal urgent care center in time. 

So yeah, don’t eat rocks.