The first step to ensure the right care and maintenance of your natural stone surfaces is to understand the type of stone you have in your house. Here is some information about the geological classification and composition of natural stone. It will help you identify the best cleaning products and proper cleaning procedures for your natural stone.
Get to Know Your Stone
According to the geological processes that resulted in their formation, natural stones are classified into
- Igneous – granite
- Sedimentary – limestone, travertine, onyx, sandstone
- Metamorphic – marble, serpentine, slate, quartzite, soapstone
Additionally, stones of these categories can be classified according to their composition into siliceous stone and calcareous stone.
Siliceous stone (sandstone, slate, quartzite, soapstone, granite, brownstone, and bluestone) is made mainly of silica or quartz-like particles. It tends to be durable and generally resistant to most acids found in your kitchen or bathroom. But still, acidic cleaners are not recommended because these stones may contain trace levels of minerals that are sensitive to acids.
Calcareous stone (marble, limestone, travertine, and onyx) mainly consists of calcium carbonate. This chemical compound is commonly found in natural stone, pearls, and shells. Since calcium carbonate is sensitive to acidic solutions, calcareous stone often requires different cleaning procedures than siliceous stone. Typically, mild, non-acidic cleaners are recommended.
Routine Care Tips
Follow these easy tips to keep your natural stone surfaces beautiful and ensure they last a lifetime.
- Protect countertop surfaces. Use a coaster under glasses that contain citrus juices or alcohol. Use trivets or placemats to protect the natural stone from heat.
- Protect floor surfaces inside and outside an entrance with non-slip mats or rugs. This way, you'll minimize the dirt, sand, and grit that may scratch the natural stone floor.
- Dust mop interior natural stone floors regularly, using a clean non-treated dry dust mop.
- If you use vacuum cleaners, make sure that their metal or plastic attachments or the wheels are not worn because they may scratch the stone's surface.
- Blot any spills immediately using a paper towel. Never wipe the area because it will spread the spill. Instead, you should flush the area with clean water and mild soap and rinse it several times. Use a soft cloth to thoroughly dry the area. Repeat this procedure several times if necessary.
Here are general recommendations for the cleaning of your natural stone surfaces.
- You should clean natural stone surfaces with a stone soap, neutral cleaner, or a mild liquid dishwashing detergent and warm water.
- Always follow the recommendations of the manufacturer of cleaning products because an excessive concentration of soap or cleaner may leave a film on a stone surface and cause streaks.
- It's better to use a clean rag mop on floors and a soft cloth for other surfaces.
- After washing the surface with a soap solution, you should rinse it thoroughly with clean water to remove all traces of soap or cleaner solution and dry it with a soft cloth.
- It's possible to minimize soap scum in baths and other wet areas by using a squeegee after each use. Soap scum can be removed with the help of a non-acidic soap scum remover. You can also use a solution of ammonia and water (solve about 1/2 cup ammonia in a gallon of water). But you shouldn't use an ammonia solution frequently because its overuse may eventually dull the surface of some stone types.
- When cleaning an outdoor pool, patio, or hot tub areas, you should flush them with clear water and use a mild bleach solution to get rid of moss or algae.
- Use specially formulated stone cleaning products that guarantee the stone's integrity.
- Don't use cleaners that contain acids, such as bathroom cleaners, grout cleaners, or tub and tile cleaners.
- Don't use abrasive cleaners such as dry cleansers or soft cleansers because they may scratch certain stones. Many commercially available rust removers contain trace levels of hydrofluoric acid that attack silicates in addition to other minerals.
- Don't ever mix chemicals together unless the manufacturer's instructions specifically tell you to do so.
- Don't use lemon juice, vinegar, or other cleaners that contain acids on marble, travertine, limestone, or onyx surfaces.
- Don't mix ammonia and bleach because this combination creates a toxic and lethal gas.
Sealing the stone is the first step in its maintenance and acts as an extra precaution against staining. But in fact, sealers are only designed to minimize stains, and they cannot entirely prevent them. So sealing does not make the stone stain proof, rather it makes the stone more stain resistant.
Actually, stone sealers are "impregnators," which don't seal the stone but penetrate below the surface and become repellent. You may need to apply an impregnator on vanity tops and food preparation areas, but it's important to make sure that it is non-toxic and safe for use.
Consult with your supplier or sealing manufacturer to learn about the specifics of the type of sealer and recommendations on the frequency of use.
Before you try to remove any stains, you should identify their types. Stains can be oil-based inorganic metal, organic, biological, paint-based, ink-based, or acid-based. If it's not clear to you what caused the stain, you should think about the likely staining agents that may have been present.
How to Remove Different Types of Stains
You can remove stains if you clean the stone surface with an appropriate cleaning product or household chemical. Here are recommendations on how to deal with different types of stains and what household chemicals to use.
Organic stains can be caused by tea, coffee, fruit, wine, tobacco, food, paper, urine, bark, leaves, or bird droppings. Such stain may have a pinkish-brown color and may disappear after you remove the source of the stain. If the stains are outdoors, you should remove the source of stains, and normal sun and rain will usually bleach the stains. And if the stains are indoors, you should clean the surface with 12% hydrogen peroxide and a few drops of ammonia.
Oil-based stains can be caused by grease, plumbers' putty, tar, milk, cooking oil, cosmetics. Such stain will darken the stone, so you should chemically dissolve them and rinse away with clean water. It's possible to clean the surface with a soft, liquid cleanser, mineral spirits, household detergent, or acetone.
Biological stains from mildew, algae, moss, lichens, or fungi can be cleaned with a diluted cleaning solution that consists of a gallon of water and 1/2 cup of any of the following: bleach, ammonia, or hydrogen peroxide. Don't mix bleach and ammonia.
Inorganic metal stains can be caused by iron, rust, copper, or bronze items. Iron or rust stains can be orange to brown in color and have the shape of the staining object, for example, nails, screws, bolts, flowerpots, cans, or metal furniture. Copper and bronze stains have a green or muddy-brown color. They result from the action of moisture on bronze, copper, or brass items that are embedded nearby. You should use a poultice to remove metal stains, but keep in mind that t's very difficult to remove deep-seated, rusty stains, and the stone may be stained permanently.
Ink stains on light-colored stones can be cleaned with bleach or hydrogen peroxide. If such stains are on dark-colored stones, they can be cleaned with acetone or lacquer thinner.
Paint stains – if they are small, you can remove them with lacquer thinner or scrape them off carefully with a razor blade. If paint coverage is heavy, it should be removed only with a commercial liquid paint stripper that normally contains caustic soda or lye. Don't use acids or flame tools to strip paint from stone. Follow the manufacturer's instructions and protect yourself with rubber gloves and eye protection.
Water spots and rings should be buffed with dry 0000 steel wool.
Etch marks can be caused by acids (e.g., from milk, fruit juices, alcohol) left on the stone's surface. Some acids may etch the finish but not leave a stain, and others will both etch and stain. You will need to contact your stone dealer or call a professional stone restorer because the etched areas will require refinishing or repolishing.
Fire and smoke damage – older stones and fireplaces may require a thorough cleaning. Since smoke contains carbonic and other acids, there may also be some etching. It's better to use commercially available smoke removers to save time and effort.
Efflorescence is a white powder that may appear on the surface of the stone as a result of the deposition of mineral salts that were carried by water from below the surface of the stone. The water evaporates, leaving the powdery substance. If it's a new installation, you should dust mop or vacuum the powder. You may need to do it several times while the stone dries out. Don't use water to remove the powder because it will disappear only temporarily. If the problem persists, you should contact your installer, who will be able to identify and remove the cause of the moisture.
Natural stone is easy to maintain, but if you find that some problems are difficult to handle, you should call your professional stone supplier, installer, or restoration specialist.