I’m pretty sure these are just typical creek rocks. I was surprised to find the 4 triangular ones all in one sieve-full. I don’t find a lot of flat, smooth triangular ones ever. I found several more later. The Little Rock on the left has a very definite rectangular notch near the bottom, on one side. I see a lot of broken rocks. Never one quite like this. Finally far right rock, one side appears to have faceting. I can’t see it being an artifact. But again, I don’t usually find any like this. Just thought I’d share.