I found this a very long time ago and I do not remember wear I found it. I do remember that when I found it I thought that was a piece of pottery. It looks a little like pottery but I do not know much about pottery. If it is pottery, how old is it? Also,it ha a bit of a curve to it .
Looks to be a rock.
On the edges, even tho worn by natural forces, it still should show man-made coils
and the flat surface has many random inclusions, so low quality material (clay?), to heat and use....