Marble needs to be handled with care to maintain its appearance. For routine cleaning, sponge marble with warm water and a mild, neutral detergent. Rinse and dry with a soft cloth. Wipe spills promptly; acids in alcohol and fruit juices are particularly damaging. Marble often comes with a protective sealer that helps prevent staining; reapply coating (available at hardware stores) once a year. For tough stains, try a poultice treatment (also available at hardware stores); reseal the stone afterward.