Natural Stone Maintenance
Granite, Marble and quartz can be installed in a variety of finishes – polished, honed, leathered, antiqued etc. It is important to know that the type of finish will not impact the type of cleaning product you use. Here are some tips to help you keep your stone looking new, year after year:
- Use coasters, especially under glasses containing alcohol or citrus juices.
- Even though many stones are heat-resistant, it is recommended to use trivets or mats.
- Blot all spills with paper towels immediately. Rinse with clear water and mild soap as many times as needed. Dry with a soft, clean cloth.
- Sand, dirt and grit are abrasive and can damage natural stone. Regular dust mopping floors is recommended. Use a clean non-treated dry dust mop.
- If using vacuum cleaners, be sure to check the metal or plastic attachments or the wheels are not worn as they can scratch some stones.
- Use a clean rag mop for the floors and a clean, soft cloth for other surfaces.
- Clean stone surfaces using a mild liquid dishwashing detergent or a neutral cleaner and warm water. Avoid concentration of cleaner or soap that may leave a film or cause streaks on the stone.
- After applying the soap or cleaner, rinse thoroughly and dry with a clean, soft cloth.
- If needed, change rinse water frequently.
- In indoor wet areas like the shower, avoid soap scum by using a squeegee after each use. To effectively remove soap scum, use a solution of ammonia and water: about half cup ammonia to one gallon of water; or use a non-acidic soap scum remover. Caution: Overuse of ammonia solution may dull the surface of some stone types.
- In outdoor areas like the hot tub areas, flush with clear water. Use a mild bleach solution to remove moss.
- For cleaning different types of stains, refer to our Stains section below.
Cleaning Specific Stains
(iron, rust, copper, bronze)
Iron or rust stains are orange to brown in color and follow the shape of the staining object such as nails, bolts, screws, cans, flower pots, metal furniture. Copper and bronze stains appear as green or muddy-brown and result from the action of moisture on nearby or embedded bronze, copper or brass items. Metal stains must be removed with a poultice. Deep-seated, rusty stains are extremely difficult to remove and the stone may be permanently stained. To make and apply a poultice call a stone professional (recommended); or go to http://www.marble-institute.com/poultice for more information.
(coffee, tea, fruit, tobacco, paper, food, urine, leaves, bark, bird droppings) May cause a pinkish-brown stain and may disappear after the source of the stain has been removed. Outdoors, with the sources removed, normal sun and rain action will generally bleach out the stains. Indoors, clean with 12% hydrogen peroxide (hair bleaching strength) and a few drops of ammonia.
(grease, tar, cooking oil, milk, cosmetics)
An oil-based stain will darken the stone and normally must be chemically dissolved so the source of the stain can be flushed or rinsed away. Clean gently with a soft, liquid cleanser with bleach OR household detergent OR ammonia OR mineral spirits OR acetone.
(algae, mildew, lichens, moss, fungi)
Clean with diluted (1/2 cup in a gallon of water) ammonia OR bleach OR hydrogen peroxide. DO NOT MIX BLEACH ANDAMMONIA! THIS COMBINATION CREATES A TOXIC AND LETHAL GAS!
(magic marker, pen, and ink)
Clean with bleach or hydrogen peroxide (light colored stone only!) or lacquer thinner or acetone (dark stones only!)
Small amounts can be removed with lacquer thinner or scraped off carefully with a razorblade. Heavy paint coverage should be removed only with a commercial “heavy liquid” paint stripper available from hardware stores and paint centers. These strippers normally contain caustic soda or lye. Do not use acids or flame tools to strip paint from stone. Paint strippers can etch the surface of the stone; re-polishing may be necessary. Follow the manufacturer’s directions for use of these products, taking care to flush the area thoroughly with clean water. Protect yourself with rubber gloves and eye protection, and work in a well-ventilated area. Use only wood or plastic scrapers for removing the sludge and curdled paint. Normally, latex and acrylic paints will not cause staining. Oil-based paints, linseed oil, putty, caulks and sealants may cause oily stains. Refer to the section on oil-based stains.
- Water and Spot Rings
(surface accumulation of hard water)
Buff with dry 0000 steel wool.
- Fire and Smoke Damage
Older stones and smoke or fire stained fireplaces may require a thorough cleaning to restore their original appearance. Commercially available “smoke removers” may save time and effort.
- Etch Marks
Etch marks are caused by acids left on the surface of the stone. Some materials will etch the finish but not leave a stain. Others will both etch and stain. Once the stain has been removed, wet the surface with clear water and sprinkle on marble polishing powder, available from a hardware or lapidary store, or your local stone dealer. Rub the powder onto the stone with a damp cloth or by using a buffing pad with a low-speed power drill. Continue buffing until the etch mark disappears and the marble surface shines. Contact your stone dealer or call a professional stone restorer for refinishing or re-polishing etched areas that you cannot remove.
- Scratches and Nicks
Slight surface scratches may be buffed with dry 0000 steel wool. Deeper scratches and nicks in the surface of the stone should be repaired and re-polished by a professional.
Cleaning Agents & Chemicals
- Oil-Based Stains
Poultice with baking soda and water OR one of the powdered poultice materials and mineral spirits.
- Organic Stains
Poultice with one of the powdered poultice materials and 12% hydrogen peroxide solution (hair bleaching strength) OR use acetone instead of the hydrogen peroxide.
- Iron Stains
Poultice with diatomaceous earth and a commercially available rust remover. Rust stains are particularly difficult to remove. You may need to call a professional.
- Copper Stains
Poultice with one of the powdered poultice materials and ammonia. These stains are difficult to remove. You may need to call a professional.
- Biological Stains
Poultice with dilute ammonia OR bleach OR hydrogen peroxide.
CAUTION: DO NOT MIX AMMONIA AND BLEACH! THIS COMBINATION CREATES A TOXIC AND LETHAL GAS!
Cleaning Specific Stains Reproduced from http://www.marble-institute.com/consumers/stains/