I've built a granite tile countertop. However, there is no bullnose, or rounded tiles that match my pattern available. What is the best way to round over the edges as the cut edges are quite sharp. I've been told to use a belt sander. But what grit belt and what composition of abrasive on the belt? I'd really like to use my router with a roundover bit. Is there such a bit available that will cut/grind the granite?