I found this on my cousins farm in SW PA this summer. It is made of solid rock. It definitely has wear in the cup area and fits really well in the hand.
Backside
In the Hand
It may be the form fitting earth which hardened into rock around a concretion. To verify 100% would be impossible from a photo. One would have to take into account the other material found in association with the rock to have some sort of a percentage guess if it is, or is not an Indian made artifact.
You do not mention if any other relics or debitage is found in the area where this was found, and if any were in the area, how close and it what association.
That’s a piece I would have carried home but I’m not too familiar with non-flint artifacts. I hunt SW PA also and would like to see some of your other finds. It’s good to see another member from SW PA.
I found it in an old mountain stream that appeared to be almost dried up. It was close to the bank in a pile of stream rubble. I thought it was an old crock at first because it was covered in mud. Unfortunately I got called out to work and had to hit the trail. I haven't had a chance to get back down there but hopefully in the spring. It is pretty remote.