Diamond Polishing Pads What are diamond polishing pads used for? Diamond polishing pads contain industrial diamonds bonded with resin, and are used to polish marble, granite, terrazzo, concrete, limestone and sandstone to a smooth, glass-like finish with a series of steps starting with the lowest grit to the highest grit. How to Polish a Surface Using a Diamond Polishing Pad? Getting a high-gloss polished surface is a long process that requires time and patience. For best results, don't skip any steps. 1. Purchase a set of quality diamond polishing pads and backing pads. 2. Mount the backing pad to your variable speed wet/dry grinder. 3. Make sure your work surface is securely fixed and will not slide. 4. Mount the 50-grit sandpaper to the grinder and start polishing from left to right at a low speed of less than 1,000 RPM. Polish until most of the saw marks and scratches on the surface are removed. 5. Switch to a 100-grit polishing pad and repeat the same process. You should not see any visible saw marks or scratches after completing this step. 6. Switch to 200-grit and repeat the process. 7. Switch to 400-grit sandpaper and repeat this step. After completing this step, you should see the granite begin to shine. 8. Gradually increase to 800, 1,000, 1,500 grit. You will see a shiny, gleaming surface. 9.Sand with 1,500 grit sandpaper. At this point, you will see a shiny, glassy surface.