It sure looks like a rolling pestle to me, I have only seen one found personally, and it was years ago. Its hard to tell how much polish it has from the pics, but im sure there are others here with more knowledge that will be able to tell. If it is thats a great find.
It’s a lot smaller than most roller pestles I’ve seen, judging by the dime. That type of pestle usually requires some heft to crush dried corn or nuts.
It could still be something small for grinding, it should have some polish or smoothed areas on the ends.