The little gray thing looks like it has been shaped and polished in the view where it is standing on the side need some more photos of it, other looks like rock. but could be hammer stone or pecking stone.
Here are some more pictures. I wasn't sure about the black one but feel fairly certain the other is an artifact. Not sure if you can see in the photos or not, but the indention runs around the rock.
I should also add that it was found on our family farm where many artifacts have been found over the years. Here is a picture of a few small things I have found over the last couple months. The piece in question was found very very close to these.