@glitterbag,
You're just wrong, I'm a small rock in yard connoisseur. (This one is left over concrete, this is stone).
Contractors, even the best, tend to be loose about concrete bits. Virtually none of us ever demanded them get it all out of there in specifications. This is usually minimal but can be a problemo with larger dumps.
Anyway, I don't need to buy or steal rocks. Hiss.