Paging All Archeology Types?

Hello, internets! Paging people who know something about archeology, maybe? I found this thing, that I think is maybe a spearhead? Or something similar? I found it in September of 2001 when I was at my friend’s place on Vinalhaven, off the coast of Maine. It was in the shallow water right off the beach. At the time, I had just completed a heroic dose of mind-expanding natural plants during which I imagined that I was some sort of Native American healer, so you can only imagine my joy at finding what I thought was a token (what does Ayla call them, the things she puts in her amulet? A totem?) or a sign from the universe or something.

So. It is this thing. Next to a penny for scale-reference. What is this thing? I truly hope it is actually a thing and not just a random rock that my brain decided was a thing. It does look like it was hammered or chipped away at or something like that.  It's not sharp like a spear but maybe it is some other sort of tool? Dr. Jones? Anyone?