I found an item called a plummet. It’s a fishing weight, used to weigh down their nets when they were fishing. I found it on a river bank.
Plummet or axe head?
I should have mentioned the size. It’s about 2 1/2 inches long. So too small for an axe head.
Very nice find! 
Rule 1A, Sub-section 7:
Never post your crimes on the internet.
You found a rock. A perfectly ordinary rock. 
(Only partially kidding)
I have found 20+ artifacts in my yard, mostly broken or unfinished flint scrapers and points. My garden was near the top of a hill overlooking a creek full of stones (literally named Rock Creek) with a year-round freshwater spring. My guess is that it was a good spot to camp, look for usable stones, and sit around making tools. The artifacts I find look like they could be rejects from the stone knapping process. The one usable item I found there was unlike all the other pieces. Rather than knapped flint, it is a 3/4 grooved ground granite axe head, probably 2 to 5 thousand years old. It’s a bit scratched up from being hit by farm implements. The hilltop was a corn field for many years.
In my case, I don’t buy or sell artifacts, I own the property, the artifacts are still on the property where they were found, and I haven’t seen anything that makes me think it was a gravesite, so I don’t think I have broken any laws by bringing these pieces in my house.
Do your walls ever bleed at night?
Only on Tuesdays. The ghastly wails are on Thursdays and the mysterious footsteps are scheduled for weekends.
In my defense I originally thought it was a nodule when I put it in my pocket. Then, when I looked more closely at it later, I realized it was something different.
Arrow heads used to be easy to find. I haven’t found very many since high school. I still look on camping trips but the campgrounds have been picked clean.
I always wondered if every Indian made bows & arrows or if one dude in the tribe specialized and made them.