Natural Stone Care

The natural stone you have purchased for your home or office is an investment that will give you many years of beautiful services. Simple care and maintenance will help preserve your stone's beauty for generations to come. This brochure has been developed to offer routine cleaning guidelines as well as procedures for stain removal should it become necessary.

You should call a professional restoration company if you experience problems.

Care and Precautions
Use coasters under all glasses, particularly those containing alcohol or citrus juices. Many common foods and drinks contain acids that will etch or dull the surface of many stones. Do not place hot items directly on the stone surface. Use trivets or mats under hot dishes and placemats under china, ceramics, silver or other objects that can scratch the surface.

Cleaning Procedures And Recommendations

Dust mop interior floors frequently using a clean non-treated dry dust mop. Sand, dirt and grit do the most damage to natural stone surfaces due to their abrasiveness. Mats or area rugs inside and outside an entrance wil1 help to minimize the sand, dirt and grit that will scratch the stone floor. Be sure that the underside of the mat or rug is a non-slip surface. Normal1y, it wil1 take a person about eight steps on a floor surface to remove sand or dirt from the bottom of their shoes.

Do not use vacuum cleaners that are worn. The metal or plastic attachments or the wheels may scratch the surface.

Clean stone surfaces with a few drops of neutral cleaner, stone soap or a mild liquid dishwashing detergent and warm water. Use a clean rag mop on floors and a soft cloth for other surfaces for best results. Too much cleaner or soap may leave a film and cause streaks. Do not use products that contain lemon vinegar or other acids on marble or other calcareous stones. Rinse the surface thoroughly after washing the soap solution and dry with a soft cloth. Change the rinse water frequently. Do not use scouring powders or creams; these products contain abrasives that may scratch the stone.

In the bath or other wet areas, soap scum can be minimized by using a squeegee after each use. To remove soap scum, use a non-acidic soap scum remover or a solution of ammonia and water (about 1/2 cup ammonia to a gal10n of water). Frequent or over-use of an ammonia solution may eventual1y dul1 the surface of the stone.

Vanity tops may need to have a penetrating sealer applied. Check with your installer for recommendations. A good quality marble wax or non-yellowing automobile paste wax can be applied to minimize water spotting.

Stone Colors and Appearance

Granites and marbles are quarried throughout the world in a variety of colors with varying mineral compositions. In most cases, marbles and granites can be identified by visible particles at the surface of the stone. Marble will normally show "veins" or high concentrations. The minerals in granite will typically appear as small flecks distributed uniformly in the stone. Each type of stone is unique and will vary in color, texture and marking.

In food preparation areas, the stone may need to have a penetrating sealer applied. Check with your installer for recommendations. If a sealer is applied, be sure that it is non-toxic and safe for use on food preparation surfaces. If there is a question, check with the sealer manufacturer.

Sandstones vary widely in color due to different minerals and clays found in the stone. Sandstone is light gray to yellow or red. A dark reddish brown sandstone, also called brownstone, has commonly been used in the northeastern United States and Canada. Bluestone is a dense, hard, fine-grained sandstone" of greenish-gray color and is quarried in the eastern United States.

In outdoor pool, patio or hot tub areas, flush with clear water and use mild bleach solution to remove algae or moss.

Know Your Stone

Natural stone can be classified into two general categories according to its composition: siliceous stone or calcareous stone. Knowing the difference is critical when selecting cleaning products.

Limestone is a widely used building stone with colors typically light gray, tan or buff. A distinguishing characteristic of limestone is the presence of fossils that are frequently visible in the stone surface.

Slate is dark green, black, gray, dark red or multi-colored. It is most commonly used as a flooring material and for roof tiles and is often distinguished by its distinct cleft texture.

Siliceous stone is composed mainly of silica or quartz-like particles. It tends to be very durable and relatively easy to clean with mild acidic cleaning solutions. Types of siliceous stone include granite, slate, sandstone, quartzite, brownstone and bluestone.

Spills and Stains

Blot the spil1 with a paper towel immediately. Don't wipe the area, it will spread the spill. Flush the area with plain water and mild soap and rinse several times. Dry the mild soap and rinse several times. Dry the area thoroughly with a soft cloth. Repeat as necessary. If the stain remains, refer to the section in this brochure on stain removal.

Calcareous stone is composed mainly of calcium carbonate. It is sensitive to acidic cleaning products and frequently requires different cleaning procedures than siliceous stone. Types of calcareous stone include marble, travertine, limestone and onyx. What may work on siliceous stone may not be suitable on calcareous surfaces.

A simple acid sensitivity test can be performed to determine whether a stone is calcareous or siliceous by applying household vinegar with an eyedropper. Select an out of the way area and apply a drop about the size of a quarter. If the stone is calcareous, the acid drops will begin to bubble or fizz vigorously.

Stain Removal

Identifying the type of stain on the stone surface is the key to removing it. If you don't know what caused the stain, play detective. Where is the stain located? Is it near a plant, a food service area, an area where cosmetics are used? What color is it? What is the shape or pattern? What goes on in the area around the stain?

Stone Finishes

A polished finish on the stone has a glossy surface that reflects light and emphasizes the color and marking of the material. This type of finish is used on wal1s, furniture tops and other items, as well as floor tiles.

Surface stains can often be removed by cleaning with an appropriate cleaning product or household chemical. Deep-seated or stubborn stains may require cal1ing a professional. The following sections describe the types of stains that you may have to deal with and appropriate household chemicals to use.

A honed finish is a satin smooth surface with relatively little light reflection. General1y, a honed finish is preferred on floors, stair treads, thresholds and other locations where heavy traffic will wear off the polished finish. A honed finish may also be used on furniture tops and other surfaces.

Types of Stains and First Step Cleaning Actions

Biological (algae, mildew, lichens, moss, fungi) Clean with dilute (1/2 cup in a gallon of water) ammonia OR bleach OR hydrogen peroxide. DO NOT MIX BLEACH AND AMMONIA! THIS COMBINATION CREATES A TOXIC AND LETHAL GAS!

Oil-based (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.

Organic (coffee, tea, fruit, tobacco, paper, food, urine, leaves, bark, bird droppings) May cause 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.

Metal (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 (a liquid cleaner or chemical mixed with a white absorbent material to form a paste). Deep-seated, rusty stains are extremely difficult to remove and the stone may be permanently stained.

Water Spots and Rings (surface accumulation of hard water) Buff with dry wool steel wool. Scratches and Nicks Slight surface scratches may be buffed with dry wool steel wool. Deeper scratches and nicks in the surface of the stone should be repaired and repolished by a professional.