Polishing the edges of a granite countertop can be pretty labor intensive and requires a delicate touch. If you decide to give it a try, you’ll need to use a grinder or stone polisher equipped with various grit diamond pads (these may be rented at tool rental centers). The pads start at 50 grit and go up to 3000 and more. If your granite has already been partially polished, you can skip the lower grits