It looks like chert, and it has been flaked. I have 2 guesses. 1. Someone was learning the "How to's" of making arrowheads. 2. Someone was trying to form an effigy.
The problem I have with it is, some of the flaking looks too sharp and fresh. did you find it in a farming area?
Sometimes a piece like that will get trapped in some cobbles sideways and then a bigger cobble will wash over it and give it a fresh break that looks chipped. imo if it was ancient all the material should be the same color especially if found in a creek. Hang onto it though I could be wrong.