Polishing edges of granite tiles is time consuming and difficult. And in the end, the result isn't a modern day attractive solution. While granite is desireable, the old way of polishing edges isn't. There is a company with a website http://Bedrockcreations.net which manufactures granite tile edges, corners, tiles, and quarter rounds. Everything you need to create a really nice countertop.
I am a remodeling contractor and have used the Bedrock Creations kitchen in a Box countertop system several times. Very impressive and easy to install. No polishing, no fabrication. Just cut and install.