Restore marble by cleaning, repairing, honing and polishing the surface. Remove deep stains using poultices of soft paper and cleaning chemicals. Protect marble surfaces by applying sealant annually and wiping spills as soon as they happen.
Because marble is soft, porous stone, do not use acidic substances when cleaning it. Instead, use a mild solution of dish soap and warm water or diluted ammonia. To remove stains from tea, coffee or soft drinks, prepare a poultice of tissue paper, 20-percent peroxide and a little ammonia. Cover the poultice with plastic wrap held down with masking tape, and leave it in place for several hours. Spread corn starch over oil stains, and after 24 hours clean the area with detergent and a brush.
Use marble repair compound from marble sellers or home improvement stores to fill cracks in marble. When marble surfaces become dull, hone them using an oscillating tool. To polish marble, strip the surface using a marble stripping agent, rinse it with water, and let it dry. Apply polish in a side-to-side motion using a handheld rotary buffer or floor buffer. Apply polish three times to get the best results.
To keep marble clean and polished, use coasters on tabletops when serving drinks. Wipe up spills immediately, clean with lukewarm water, and dry the surface using a clean cloth.