The quality of the flint and knapping makes me guess it was not used as a hoe. It looks like its to sharp. Probably a ancient personal weapon--tomahawk. It is a very well made and it looks like from the chip on the blade that somebody got whacked with that thing. Thanks for the pic. I really how unique it is.
I'd say it's unfinished. It's got the general shape of a hoe blade but a little small. I can't see where you would attach it to be an axe, but could be either one, I guess.