Uncle Jesse,

I'm pretty sure it's not a mortar and pestle since the hole is only about 1 1/2 inch in diameter and the bottom of the hole is flat rather than rounded as you would see in a pestle. Also, the inside of the hole is raw granite and not polished. I actually looked at the bottom of it just now for the first time (I've only had it about 4 years now), and it was originally sold by a fancy bed and breakfast in North Georgia for $27. I bought it for $2 at a local Goodwill store. Anyway, it works great for what I'm using it for.

Jim