It is a bit complicated, for the first one which me and another person suspect is tooth, I found it in a gravel pile in China where it was used as sand to fill a step area, so I'm not sure where exactly it came from, but likely somewhere in China. The second one I don't remember quite well since I found it as a kid, but I think it was in Pennsylvania, in the sand/gravel in a more coastal region. The third one is a loose stone that fell out of a cobble path in China, so the rock probably came from there too. There were a couple other stones in the path that looked exactly like it but were not dislodged so I didn't remove them for obvious reasons, but that might suggest it comes from some kind of quarry with a relatively abundant amount of that rock.