Natural Stone is not manufactured; it is a product of nature. Blocks are removed from the quarry, slabs are cut from these blocks, and the slabs are further fabricated into the final stone to be installed. Each block is different; each slab is different. Skillful blending or matching of the dimension stone blocks, veneer panels, tops, etc., results in a beautiful blending of nature’s variety and man’s design. In contrast to the uniformity of materials produced by machine or assembly line, stone’s naturally varied appearance has wonderful character. “Uniformity of material,” when applied to natural stone, is a term of relative value that needs to be understood when making a selection.
Granite is the most popular stone type used in countertop applications today. Granites are some of the hardest of the common countertop stones, offering high levels of resistance to abrasion and scratching. Granites are made up of several different minerals, each mineral having a different hardness. Granites contain quartz, feldspars, biotite, amphibole, ferrous titanium oxides, and other mineral combinations. Limestone is a sedimentary stone with at least 50% calcite or calcium carbonate content. Almost all limestone is composed of grains or fragments of biologic origin, ranging from fossils to dinosaur bones. Most limestone is marine in origin, composed of micro-sized fossils of marine organisms like the shells found on most beaches. It is very common to find pieces of shells in limestone tiles.
Marble is a metamorphic rock predominantly consisting of calcite, dolomite and crystals. Onyx originates from deposits of limestone caverns, where it forms stalactites and stalagmites. Onyx is formed by gentle, dripping water movement and may envelop terrestrial fossil remains. Since onyxes are formed by a process of crystallization, they are considered part of the marble family. Marbles and Onyxes typically have a diverse aesthetic appeal, accentuated by distinct veining and often bold colors. They are relatively softer than granite. Marbles can be scratched by kitchen utensils, so it is best to use cutting boards and other protective measures. Marbles can also be etched by chemical attack. Since these stones are calcium carbonate-based, they can be damaged by exposure to acidic solutions such as lemon juice, tomatoes, vinegar, etc. The use of inappropriate cleaning agents may also trigger acidic attack. Acidic solutions can permanently etch the surface of the material. The application of a sealer will reduce, but not eliminate, the vulnerability to acidic attack. For these reasons, marbles and onyxes are not recommended for use in kitchens, however they can be a good selection for bathroom vanities for example.
Slate is a metamorphic rock exhibiting “slaty” cleavage, which allows it to be split in thin sheets. Slate is formed in the water of rivers and ponds from clay accumulating in thin, flat layers at the bottom of these waterbeds. Slates are softer than granite and therefore vulnerable to scratching and abrasion. Slate has a natural cleft (not a smooth surface). The same precautions mentioned for marbles with regard to damage should be applied to slates.
Travertine is a calcium-based stone. Travertine is generated by the deposit of calcium carbonate resulting from water springs and streams running through the stone. Every time a drop in pressure or change of temperature occurs, the water releases carbon dioxide as gas, much like carbonated beverages. This gas causes holes to form in the travertine. These natural pores are still going to be present once the blocks are cut into tiles. The amount of holes depends by how compact each travertine type is and it varies greatly by the type of travertine. The pores present in the tiles can be filled with a paste made of cement and pigments. However, it is important to note that these void spaces are a distinctive character of travertine tiles and they are always going to be present to a certain extent.
A mirror-like, glossy surface that brings out the color and character of the stone to its fullest, because it optimally reflects the light.
A velvety smooth surface with little or no gloss. The degree of honing depends on the stone, but may vary from light to heavy.
A weathered, aging finish achieved when the stone is tumbled with sand, pebbles, or steel bearings. Tumbled stone may present chipped edges and imperfections created by the tumbling process. These characteristics give the stone more of a worn, old look.
A finish that replicates rustic or distressed textures. This finish tries to replicate the naturally occurring effects of the aging process.
This term usually refers to slate stones. It means a cleavage face formed when the stone is split into any thickness.
This term usually refers to slate stones. It refers to the process through which slate tiles are all calibrated to a specific thickness.
Before making final selection of a stone, take wastage into account to make certain there will be enough material to complete the project. An often-forgotten fact is that the material from a quarry today may be different from what was available six months ago. Further, there may be more than one quarry of the material. It is always recommended to order what is typically referred to as “attic stock”, a little amount of material to be kept on the side if future repairs are needed.
The final look of mixed tiles may fall short of appearance expectations, especially if the stone is variegated and veined. The installer should mix tiles from different boxes during the installation to achieve a more even, visually pleasing result in the finished surface. The homeowner should always look at the natural stone with the installer before the installation takes place. Moreover, it is highly recommended that the homeowner gets involved and discusses the stone layout with the installer in details to prevent misunderstandings from occurring.
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.
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 will 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. Normally, it will 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.
Most stones are porous and readily absorb liquids and moisture. Materials like limestone and sandstone are extremely absorbent, whereas granites and serpentine (green marble) are denser, but will still absorb liquids that are allowed to remain in contact with them for extended periods of time. The use of a sealer will help prevent staining in most situations. Even a sealed surface can stain if left in contact with a staining agent for a long period of time. Therefore, all spills should be wiped up as soon as possible, and coasters or napkins should be set when serving food or drinks on a stone bar, table, or counter top. Soft drinks, coffee, tea, and fruit juices contain mild acids and can etch the polished surface of a stone and stain quite rapidly. These should be cleaned off immediately with mild soap and warm water.
A sealer cures as a film on the stone surface. Since the material is actually covering the stone, the appearance of the stone surface may be altered by the application of this type of product. This material will provide somewhat of a sacrificial layer over the stone, and will absorb most of the wear on the countertop. Since the sealer is softer than the stone, normal use of the countertop will result in abrasion of the sealer surface and dictate reapplication to maintain the original luster of the surface. A properly applied topical sealer will normally reduce, although not eliminate, the vulnerability of calcareous stones to attack from mildly acidic solutions.
General Precautions. When any surface protection product is used, care must be taken to read and follow the Manufacturer’s written instructions accurately. This will provide the greatest benefit from the application and will guarantee safe handling of the product.
Clean stone surfaces with a few drops of neutral PH stone cleaner available at retail stores or at your local tile and stone dealer, 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 limestone. Rinse the surface thoroughly after washing with 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 surface.
In the bath or other wet areas, soap scum can be minimized by using a squeegee after each use. To remove soap scum, use an approved non-acidic soap scum remover available at retail stores or at your local tile and stone dealer.
Blot the spill 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 area thoroughly with a soft cloth. Repeat as necessary. If the stain remains, refer to the question on stain removal.
If stains do occur, a stain remover may be required. Whereas, a cleaner will wash off surface dirt, a stain remover such as a poultice will actually act to draw out deep-seated dirt and stains from the stone’s pores. Several applications of a stain remover may be required for difficult stains, and darker marbles should be tested to make sure that the stain remover will not bleach the stone. For recurring problems, and/or a very deep stain, a professional stone fabricator should be contacted. Approved stain removers are available at retail stores or at your local tile and stone dealer.
DO Dust mop floors frequently
DO Clean surfaces with mild detergent or stone soap
DO Thoroughly rinse and dry the surface after washing
DO Blot up spills immediately
DO Protect floor surfaces with non-slip mats or area rugs and countertop surfaces with coasters, trivets or placemats
DON’T Use vinegar, lemon juice or other cleaners containing acids on marble, limestone, travertine or onyx surfaces
DON’T Use cleaners that contain acid such as bathroom cleaners, grout cleaners or tub and tile cleaners
DON’T Use abrasive cleaners such as dry cleansers or soft cleansers