Things You'll Need
Acetone or clear ammonia
2 tablespoons baking soda
Plastic cling film
Plumber's putty is a soft, flexible material that is used to create waterproof seals around fixtures and faucets. While the main ingredient in this pliable paste is clay, manufacturers often incorporate oils into the mixture to create a product that remains flexible for months. Though the oils may keep the clay from drying out, they can seep into porous materials, leaving unsightly, dark stains behind. For this reason, plumber's putty should not be used on naturally absorbent surfaces, such as marble. However, if the damage has already been done, do not worry. The stain can be removed through a marble-cleaning technique known as "poulticing."
Scrape the excess putty away with a butter knife. Work gently to avoid inadvertently scratching the marble.
Swab the affected area with a soft cloth that has been dipped in acetone or clear ammonia, rinse with lukewarm water, then wipe with a clean towel to dry.
Pour 2 tablespoons of baking soda into a small bowl. Add 1 tablespoon water and stir well. Spread a thick layer of the mixture over any remaining stains.
Cover the paste with plastic cling film and seal the edges with pieces of adhesive tape.
Remove the plastic wrap after 24 hours, exposing the materials to the open air. When the poultice is completely dry, use the edge of a plastic spatula to lift the paste from the marble. Wipe the area with a wet sponge to remove any remaining residue, dry with a clean cloth, and repeat, if necessary.