How to Clean Marble
A type of calcareous stone, marble is composed primarily of calcium carbonate, which is found in natural stone, shells, and pearls. Marble is a soft, porous stone that's susceptible to staining, scratches, and acidic solutions, but with proper care it will beautifully endure for ages.
When it comes to preserving marble surfaces, Mike Loflin, Industry Research & Information Manager at the Marble Institute of America, recommends:
Preventative measures. Use coasters under all glasses, particularly those containing alcohol or citrus juices, and place hot dishes on trivets.
Protect against abrasive sand, dirt, and grit. Frequently mop interior floors using a clean non-treated dry dust mop. Minimize tracked-in dirt by placing slip-resistant mats or area rugs inside and outside entrances. If using a vacuum cleaner on marble floors, make sure that attachments and wheels are in tiptop shape; worn equipment can scratch marble.
Stay on top of spills. Immediately blot, don't wipe, spills with a paper towel (wiping spreads spills.) Flush the area with a mix of water and mild dishwashing soap; rinse several times. Dry the area thoroughly with a soft cloth. Repeat as necessary.
Don't use harsh cleaners. Never use abrasive scrubbers or rough-woven cloths that could scratch marble. Take a pass on products containing lemon, vinegar, or other acids that will dull or etch marble surfaces. Stay away from scouring powders or abrasive creams and rust removers containing trace levels of hydrofluoric acid (HF); these will damage marble.
Safe Marble Cleaning Solutions
Marble surfaces should be cleaned with soft cotton cloths and clean rag mops along with neutral cleaners, mild liquid dishwashing detergent mixed with water, or stone cleaners.
If you want to go the easy route, try a commercially available stone cleaner. Debra Johnson, Merry Maids' Home Cleaning Expert, recommends trying Take it For Granite, a spray that can be safely used daily to clean marble surfaces, including countertops, floors, and shower walls.
Prefer to make your own? Mary Findley, an Oregon-based sustainable living coach, author, and cleaning expert (GoClean.com), advises adding 1/4 cup isopropyl alcohol to a 32-ounce spray bottle and filling the bottle with water to create a cleaner for marble surfaces. If more power is needed, Findley says to add a drop of an organic liquid dishwashing detergent (that contains no phosphorous or degreasers) to the mix.
After washing marble surfaces, immediately dry with a soft cloth to prevent streaks and water spots; use a buffing motion to turn up the shine.
Marble shower walls require special attention, says cleaning expert Donna Smallin Kuper (Unclutter.com). She recommends preventing soap scum from building up by using a squeegee on shower walls after each and every shower. When dirt can't be removed with a squeegee, try a product designed for deep cleaning marble or use dry steam to break down the dirt.
Treating Stains on Marble
No matter how carefully you tend marble surfaces, stains are likely occur. Common stains that mar kitchen and bathroom surfaces include oil-based and organic stains. The Marble Institute of America has a handy guide, designed to help you identify and remove these and other types of stains.