Speaking of hard crunchy snacks. I bought a bag of almonds at a reputable mall store back in the 80's when it was sorta a heath craze. It wasn't a national brand of almonds, they were locally grown and bagged . Anyways I was going along fine biting down on them...tossed one into my mouth, crunched down...then "Oh oh".
I think it was a rock shaped exactly like an almond. It fractured my molar. That rock shaped almond got past local quality control.
From that day on, I spent thousands on that "rock almond" cracked molar tooth (to keep it), eventually getting an implant.
My jumping on the 80's health band wagon sorta cost me.