Found this on a friends ranch near the mouth of a creek. I have a really hard time believing it formed naturally this way...but I'm far from an expert. No idea what it could be. Maybe a woodworking tool? It sits completely flat on one end and comes to a perfect blunted point
Grim was trying to point out, rather elegantly, that if someone were to take the time to peck, grind and polish a stone whatsit...it would not end up looking like a crude "is this an artifact" rock. What you have is also a pretty common shape to find out there in the world of rocks. Perhaps some time ago some native feller did pick this up and transport it with the intent of improving it into a pestle but he never did. That "triangular" cross section is a very common way that type of rock can fracture.