Polished marble is a shiny and resilient natural stone often used for counter tops, vanity units and flooring. Most polished marble resists stains, but allowing water to sit on the marble for extended periods can cause etching, which will produce small dull stains and spots on the surface. To remove these spots without damaging the marble, use only marble-safe products from stone manufacturers and professionals.
Wipe the marble surface with a soft cloth dampened in warm water to remove surface dirt, dust and other contaminants. Dry it thoroughly with a clean towel.
Lightly scrub at the etching water stains with fine-grade steel wool. Only scrub as much as you need to in order to see the stains begin to fade. You may see small scratches from the steel wool appear on the marble surface. Don't worry, they will be eliminated later.
Apply a thin layer of marble polishing paste to a clean, lint-free cloth. Buff in small circles across the scratched areas of the marble. The paste will fill in the small scratches and restore the marble's polish.
Allow the polishing paste to dry and inspect the work. Apply another coat of polish if necessary to complete the polishing process.
Steel wool and polishing will not remove severe etching marks. If this method does not work, contact a professional marble or stone manufacturer for details of professional marble refinishing.