Place the granite tile as close as you can to the installation area. Use a grease pencil to draw the rounded line on it where it needs to be cut. If you are only rounding off the edges, you do not need to draw the line since you can estimate how much to remove.
Move the granite tile to an outdoor location, if possible, since the cutting process will create quite a bit of dust. Put on safety glasses and a dust mask to protect yourself.
Insert a diamond-tipped cutting blade into a tub saw and turn on the saw. Move the granite tile under the blade making sure to keep your hands away from it. Rotate the tile as needed so that the saw blade follows along the circular grease pencil line.
Remove the tile and turn off the saw. Insert a 50- to 150-grit polishing pad onto a stone polisher and plug the cord of the polisher into an electrical outlet.
Secure the granite tile in a vertical position using a table clamp with the rounded edge facing upward. Turn the stone polisher on and move the rotating pad smoothing over the rounded edge to remove the sharp jagged areas. Continue polishing the granite for three to four passes.
Turn off the polisher and switch to a 3,000- to 5,000-grit polishing pad. Turn the polisher back on and continue polishing the rounded granite edge until it is shiny and smooth like the remainder of the tile.