Identifying hammerstones and worked cobbles
Battered ends and pecked hollows — the tools that made other tools.
A hammerstone is a hard cobble used to strike flakes or crush material: look for concentrated battering and pitting on the ends or margins — crisp crushed zones quite different from river rolling, which smooths everything evenly.
Related humble tools include anvil stones (pitted central hollows), rubbers and polishers (one worn flat, silky face), and pot boilers — fire-crackled stones heated for cooking, showing crazed, reddened, angular fracture. Cupped stones with neat pecked depressions may be nutting stones or small mortars.
These identify by wear pattern, so describe exactly where the damage sits and what it looks like. A battered cobble alone is weak evidence; among flint waste or burnt mounds it completes a picture. Record dimensions, stone type, and each wear zone's position.