flint chaser and i find a few hardstones like that here in madison county illinois. thought alot about those strike marks and we think they are from the farm machinery. but after seeing a few here on t net i gues we better look closer. to the indentations. cool find.
I don't think he's referring to the plow marks, I think he's referring to the pecked out circle which looks like a nutting stone or something along those lines.