How to Remove a Stain From Carrara Marble

Like "David," many of Michelangelo's works were carved in Carrara marble.

Produced from limestone over perhaps millions of years, the quarries in Italy's Apuane mountain range yield a rich, white marble that is world-famous for purity. Once prized by Michelangelo, who sculpted many masterpieces from Carrara marble, Italians still savor the look of marble in their homes. In Italy, however, the scars and stains so easily imparted on Carrara marble stand as marks of character, almost like a picture history. In your home, you can enjoy the beauty and elegance without the marks with careful care. A poultice -- purchased or homemade -- can take out most stains.

Things You'll Need

• Soft, clean cloths
• Water, preferably distilled
• Dish soap, gentle and pH balanced
• Soft to medium-bristled brush
• Ammonia
• Industrial-strength hydrogen peroxide (20 to 35-percent strength)
• Paper towels or napkins
• Whiting (powder talc chalk)
• Plastic spatula
• Plastic wrap, baggie or garbage bag
• Masking or duct tape
• Mineral spirits
• Methylene chloride
• Oxalic acid or commercial rust removing cleaner

Instructions

1. Blot up spills immediately using a soft, clean cloth. Avoid rubbing the cloth around because this actually pushes the substance into the marble as well as spreading it in a wider area. Instead, dab and change cloths as necessary until all of it is gone.

2. Investigate the source of the soil and stain to help you determine the most effective poultice for stain removal. Look at the color, location and the formation of the stain for clues. A stain that looks like a brown splotch, found in the kitchen near the coffee pot, is likely a coffee stain, for instance, while a reddish colored stain near a plant container or metal object might be rust.

3. Mix a small amount of water -- distilled, if possible, to avoid adding chemicals or minerals -- with a few drops of gentle, pH balanced dish soap. Use a soft to medium-bristled brush to work at the area, taking care not to spread the mess. Sop up the solution with a cloth and dip your brush back in the water, reapplying and repeating. This treatment may remove some light stains if they have not yet had the chance to set.

4. Switch to a solution of one part water to one part ammonia or one part water to one part hydrogen peroxide. Consider adding a splash of ammonia to a peroxide mixture for extra cleaning strength. Dip your brush into the solution and apply to the stained area, blotting up and reapplying as necessary. Peroxides work best on organic stains such as food, makeup and other once-living materials.

5. Rinse the area thoroughly. If the stain persists, wet the area with water to block the marble pores, which aids stain removal poultices. You can find special marble poultices in the store, or make your own, trying one after the other of the poultices in what is known as a "patch test," until one works if the stain composition is unknown.

6. Prepare a poultice for organic stains, choosing between a wet or powder-based poultice. Place a thick pad of either paper towels or napkins over the stained area, either pre-soaking the paper in straight hydrogen peroxide or pouring the peroxide over top the paper, to make a wet poultice. Check to ensure you used enough peroxide to saturate the paper and provide the marble enough moisture over the stained area only.

7. 

   Use coasters, potholders and other protections for your marble.

   Create a dry poultice for organic stains, mixing powder talc chalk -- called whiting -- with enough peroxide to create a paste. The texture should be thick and somewhat sticky like peanut butter. Spread the paste over the stained area with a plastic spatula, using a coat much like jelly on bread. Cover the poulticed area with a plastic baggie, plastic wrap or garbage bag to seal the moisture in. Tape the edges with masking or duct tape and let it set for up to two days, removing once the poultice dries out and reapplying if the stain remains. The chemical works down into the marble, dissolving the stain if possible. Clean and rinse when complete.

8. Remove ink and marker stains along with many oil-based stains with either a wet poultice of mineral spirits or a dry poultice using whiting mixed with methylene chloride. Pour small amounts of methylene chloride into the powder and mix well, avoiding breathing the fumes or touching the chemical during the process. A chemical in paint thinners as well as an industrial solvent, methylene chloride is a potent material and should be used judiciously, as a last resort for inks stains.

9. Treat an iron stain with a dry poultice created from mixing whiting, oxalic acid and enough water to create a thick paste. Treat by taping the poultice in place, allowing it to dry, with removal and rinsing to complete. Use a commercial iron removal cleaning product, alternatively, following the manufacturer's instructions completely. Both methods are harsh on Carrara marble and should remain on the surface as little time as possible. Some iron actually comes from inside the marble and treatment may only lighten the stain.

Tips & Warnings

• The most common stains occur in the organic, oil, ink or rust categories. For other stain categories, many of these poultices still work, however. Consult stain removal charts for unusual stains and removal ingredients.

• Some stains are permanent. Poultices may do little more than lighten the stain in these instances.

• Treat burn marks with a poultice, then sand or refinish the marble to complete the repair.

• Seal your marble to prevent the formation of many stains.

• Ensure adequate ventilation during stain poultice application. Many of these chemicals emit harsh odors that may irritate the eyes, skin and lungs.

• Never mix bleach with ammonia -- a toxic gas will result when combined.

References

• "Old House Journal"; Cleaning a Marble Mantel; Mary Ellen Polson; 2011
• Michigan State University Extension; Marble Stain Removal; June 2003
• Housekeeping Channel; Removing Stains From Stone, Tile and Concrete; Fred Hueston
• Centers for Disease Control; Toxic Substances Portal - Methylene Chloride; February 2001
• Eurotech Marble: Removing Stains from Marble and other Natural Stones
• Natural-Stone.com; Stain Removal Basics; Frederick M. Hueston

Resources

• Amso International: The Marble Quarries of Carrara
• Arizona Tile: The Beauty and History of White Marble
• Math/Science Nucleus: Metamorphic Rock Teacher's Guide - Lesson 5 Michelangelo and Marble
• The Tile Doctor: Stone Cleaning Information
• The Rock Blog; Stain Problems; Tom Cordova