Even the highest quality polished granite will eventually show signs of wear. High-traffic floors lose their mirror finish over time, countertops develop fine scratches from daily use, and outdoor granite weathers and dulls. The good news is that granite can be re-polished to restore its original mirror finish — and in most cases, to a quality equal to or better than the original factory finish.
Signs That Your Granite Needs Re-Polishing
- The surface looks dull or hazy rather than reflective
- Gloss meter readings have dropped below 80 GU (original finish is typically 100–110 GU)
- Fine scratch patterns are visible under raking light
- The surface feels slightly rough or gritty rather than smooth
- Water no longer beads on the surface even after re-sealing
Professional Re-Polishing vs DIY
For most granite installations — particularly large floor areas or kitchen countertops — professional re-polishing by a stone restoration specialist is strongly recommended. Professional equipment achieves results that cannot be matched by DIY products.
| Professional | DIY | |
|---|---|---|
| Equipment | Planetary grinder with diamond pads | Hand buffer with polishing compound |
| Result | Full mirror finish (100+ GU achievable) | Moderate improvement (70–85 GU typical) |
| Scratches | Can remove deep scratches | Removes only superficial scratches |
| Time | 1–2 days for average kitchen | Several hours for small area |
| Cost | Higher upfront | Lower upfront |
| Best for | Floors, heavily worn countertops, restoration after damage | Maintenance of lightly dulled countertops |
The Professional Re-Polishing Process
- Assessment — The technician assesses the degree of wear, identifies any cracks, chips or deep scratches, and determines the starting grit.
- Grinding (if required) — For severely damaged surfaces, coarse diamond pads (50–100 grit) remove the damaged layer. For lightly dull surfaces, this step may be skipped.
- Progressive honing — Diamond pads progress from coarse to fine (200, 400, 800 grit), refining the surface texture at each stage.
- Polishing — Fine diamond pads (1,500–3,000 grit) or polishing powders bring the surface to mirror finish.
- Crystallisation or polishing powder — A final polishing compound is applied and buffed to achieve maximum gloss.
- Sealing — The re-polished surface is sealed with a penetrating impregnating sealer while the pores are fully open after polishing.
Re-Polishing at the Factory
If you are a granite distributor or fabricator who has received slabs with substandard polish, re-polishing can be carried out at your facility using a bridge polishing machine or portable planetary grinder. The process is the same as above but applied to individual slabs before fabrication.