- Origins and Sources
- Physical Characteristics
- Color and Pattern
- Fabrication and Finish
- Sinks and Cooktops
- Protecting the Surface
- Keeping it Clean
- Bacteria Resistance
Granite has been used as a building material since ancient times. It is one of the oldest and most durable building products available, and will far outlast the building in which it’s installed. It has become the material of choice for today’s luxury homes and offices because of its enduring beauty, and because no synthetic material can yet compare to its elegance and performance.
Products made of this stone will not depreciate with time and will continuously add value to any property where they are installed. Unlike synthetics, granite presents a surface depth that seems almost three-dimensional. It has a luminance that’s absent from other surfaces. Regardless of its finish, granite creates an immediate impression of elegance, and is considered a definite plus on any real estate broker’s checklist.
Granite is sold both in tiles and slabs, and is frequently used not only for kitchen countertops, bar tops, and vanities, but also for walls, floors, fireplace surrounds, windowsills, and even building fascia. Its unique variations in color and veining turns make each specimen a natural work of art. It is cool to the touch, and presents an image of classic grace and beauty.
Granite, being an igneous rock (formed from volcanic activity), differs from marble, limestone, and travertine in that those are sedimentary stones composed mostly of calcite, a relatively soft and common mineral derived from animal skeletons and shells. Millions of years of compression and heat below the earth’s surface turned them into stone.
Granite is one of the hardest stones available, having a rating of 7 on the Moh’s Measurement of Hardness Scale. In contrast, marble is rated only a 3. And since their main component is calcium, marble and the others are more susceptible to damage by acids such as vinegar and citrus beverages.
Several factors affect the price of granite, but the most important are supply and demand. Supply is the affected by the accessibility of the quarry, the uniformity of the stone within the quarry, and the stone’s workability. A granite that is exquisitely figured, one that contains rare colors (e.g. blue), or one that is found only in a third world country will be more costly.
Origins and Sources
Granite is believed to have been formed as long ago as 300 million years. It began as a mass of molten rock, estimated at 1300 -1400 degrees F., formed by volcanic activity about 11-12 miles underground. Forces of nature caused the magma to gradually rise to the surface where it began to cool very slowly over the next million years or so, solidifying into granite.
Over time, the land above it eroded, leaving a scattering of granite quarries all over the world. Aside from the traditional sources, such as Italy, USA, and Canada, popular granite producing areas now include India, China, many African nations, much of mountainous South America, and the northern European countries.
Granite is composed primarily of feldspar, quartz, and mica. It may also contain hints of muscovite, biotite, hornblende, and pyroxene and other minerals. These minerals are what give it its various colors. The white mineral grains in granite are feldspar, our planet’s most abundant rock, which makes up about 60% of the earth’s surface. The light gray, glass-like veins are quartz, and the black, flake-like veins are biotite or black mica.
Other minerals imbue the stone with a rainbow of colors, depending on their source, and these varieties are often given unique names. One coarse grained type, for example, is called pegmatite, which is often rich in rare elements such as uranium, tungsten, and tantalum.
Granite is drilled and blasted from the quarry in large blocks, cut into slabs by a gang saw, and polished to uniform thickness by automatic polishing machines. The size of the slabs will vary from quarry to quarry, but are rarely more than 10 ft. long. It is cut and fabricated into countertops using diamond saw blades or drill bits.
Granite is crystalline in structure, so it always has tiny pits or spaces between the various mineral crystals. They are not visible prior to polishing, and usually remain unobtrusive on finished pieces once the surface is highly polished. Granite also contains natural fissures that may appear to be cracks, but they are not structural defects and will not impair the function or durability of the material. They occur naturally and are considered to be part of the beauty of stone.
Granite is not recommended to customers who prefer surfaces that are perfectly uniform in color and pattern, those that are totally free of blemishes. For those individuals, engineered stone would be the preferred choice.
Due to quarry variances, granite slabs are sold in random sizes. A typical slab will measure 4-5 ½ ft. wide and 7-9 ft. long. This is most important in dealing with islands, since most people want an island with no seams. Therefore, it’s important to know in what size a preferred slab is available before making a selection. The only way to know is to call the fabricator each time an order is placed because slab sizes can change.
Granite is very heavy. Most varieties are available in both 2cm (3/4″) and 3cm (1-1/4″) thicknesses with a tolerance of +/- 3 mm. Our more popular thickness is 3cm. Finished slabs weigh approx 12-13 lbs per sq. ft. in 2 cm thicknesses, and approx 18-19 lbs per sq. ft. in 3 cm (1.18″) thicknesses. Therefore, an 8 ft. top 3 cm thick will weigh between 144 and 152 lbs.
Granite is not always a uniform thickness. Customers should be aware that their slab may vary in thickness as much as a quarter inch over the length of the slab. The installer must compensate for these variations with additional support, as needed, at the time the granite is installed.
Although granite is very durable when it’s installed properly, it’s not unbreakable. It can be chipped or cracked if it’s struck a sharp blow by a heavy object. It can also break if it’s dropped during installation. It is not flexible, and will crack if it is forced to twist or bend. Therefore, granite should only be handled by professionals and must always be adequately supported by proper framing or cabinetry.
Granite is the least susceptible of all natural products to scratches. If not abused, it will hold its luster forever. However, harsh chemicals and abrasive cleaners will dull the surface over time.
Granite will not scorch or burn through ordinary use. It’s also resistance to stains. However, a few varieties may absorb some moisture with prolonged contact. Usually, no evidence remains when the liquid is removed and the granite dries, but this could be a problem with dark pigmented liquids or oils. A stone sealer should always be applied to its surface after installation.
The quality of granite is highly subjective. The “best” granite is the one that best suits the need of the buyer, both for aesthetic and practical reasons. However, it is often rated on its luster when polished, its surface porosity, and its mingling of colors. Nearly all examples are quite suitable for counters, floors, and walls. There are lower grades available, but few are sold by reputable suppliers. The quality of the finished product lies more in the workmanship of the fabricator than in the product itself.
The Selection Process
Many customers are concerned about cost, but we sell several varieties of granite that are attractively priced. Once a customer sees that it will fit into the budget, the next step is to choose a color. But before this can be done, the buyer must decide whether the countertop will be the main focal point in the room, or another feature such as cabinetry.
Sometimes the customer may decide to mix and match countertop materials, with the outside counters being one material and the island being another. In some cases, an island may even be split into two levels, with granite installed on one side only.
Color and pattern
Granite is a primordial stone with naturally occurring variations in color, tone, granularity, pattern, etc. These variations, referred to as ‘movement’, should be expected and are the source of its natural beauty.
Our Best Selling Granite Patterns/Colors
Note: Due to variations in monitors and computer displays,
the sample colors shown here may not display accurately.
Also, keep in mind that the veining in the granite can effect color perception. Sometimes two different grain sizes occurring in the same slab will appear to be of a different color. Mineral concentrations may cause patches that appear darker or lighter.
Consumers who are less acquainted with the material may expect the granite ordered to be identical to the sample they were shown. While the samples are intended to represent the quarry’s product, each slab may differ slightly in color and veining. Indeed, even a single granite slab will have color variations from one end to the other. This lack of predictability gives the product its unique character and adds an element of nature into human-designed spaces. Indeed, each specimen is an original artwork.
For these reasons, we always ask our clients to examine the actual slabs of material from which their tops will be cut. The sample in our showroom may differ from the slabs currently available at the fabricator’s warehouse. They may have been mined from a different part of the quarry or they may have occlusions or color variances that give them a different appearance.
While color options are numerous, it’s usually best to choose a specimen that is stocked locally because of the cost difference. If a slab has to be special-ordered, the freight would be prohibitive and the lead-time could be several weeks. In addition, the customer would have to agree to accept the color and markings sight unseen.
Fabrication and Finish
Fabrication costs can significantly affect the final price. Generally, the more complex the shape of the project and particularly the shape of the finished edges, the higher the price will be. Fortunately, a single thickness plain polished edge makes an excellent appearance and most customers choose this standard, especially when using the 3 cm (1.18″) thickness.
Occasionally, a customer will want a custom edge pattern, possibly to match the edge to detailing on the cabinetry, and this can also be done. But keep in mind that if the fabricator has to buy custom cutting bits, he will add their cost to the price.
Fabricators may sell finished pieces, but slabs are always sold intact. The price includes the cost of transportation, making field measurements and templates, cutting, polishing, delivery, and final installation. The total material required is determined by the layout and the amount of waste. The fabricator will try to lay out each job so as to minimize waste yet maximize the natural beauty of the veining and pattern.
Granite is usually polished to a high gloss finish. It is also available in a “honed” finish if desired, but this will increase the cost. Granite can be finished a number of styles:
- Abrasive finish – flat non-reflective surface, usually recommended for exteriors
- Acid Etched finish -rusticated through the application of abrasive or acidic agents
- Brushed finish – brushed with a coarse rotary-type wire brush
- Brush-hammered finish-varied texture, subtle to brushed by a mechanical process
- Flamed/thermal finish-roughed by intense heat flaming to expose grains of stone
- Honed finish – satin surface with little or no gloss
- Polished finish -glossy, bringing out the full color and character of the stone
- Sandblasted finish- matte textured with no gloss. Recommended for exterior use
Sinks and Cooktops
Usually, a sink will be mounted somewhere on the top. Sinks may be the self-rimming type that are mounted on top of the countertop, or under mount sinks that are installed by clips attached to the underside of the countertop and having a finished bowl opening. Sinks may be stainless steel, cast iron, and synthetic stone, or a number of other materials.
When choosing a sink, it is vitally important to make certain that the sink will fit in the cabinet in which it is to be mounted. Keep in mind that the cabinet must always be wider than the sink, i.e. a 30″ sink will not fit in a 30″ cabinet. There must also be ample room available for the faucet of your choice and any other accessories you may select.
Due to their weight, an under-mounted cast iron sink cannot be anchored solely to the granite top, but must have a support frame built into the cabinet by a carpenter.
If a cook top is to be mounted in the granite, be sure that there is room inside the cabinet to hold the top and any pop-up vents that will be installed with it.
All of these items must be on the job site before a template can be made.
Note: In the case of both sinks and cooktops, allowances must be made for the thickness of a backsplash when measuring for the placement of these fixtures. If thicker granite is used, a wider space will be needed.
If the top is replacing an existing top, be aware of the differences in thickness of the two materials. Any upper cabinetry that currently rests on the existing top will probably not reach the granite, so adjustments will have to be made.
All ordinary cabinets with frames that are securely fastened to the wall will easily support granite countertops. The weight of an average person standing on the cabinet puts more strain on the cabinets than a granite countertop.
Counter tops are measured in much the same way as other solid surfaces. First, a template must be made to use as a pattern. For this reason, base cabinets must be permanently anchored in place before measurements can begin. They are to be installed only by the fabricator who will assume responsibility for a proper fit. Improper installation of kitchen countertops may void the manufacturer’s warranties and result in damage to your fine surface or other areas of your kitchen, such as cabinets, drawers, sinks, and fixtures.
Be sure to allow sufficient lead time for the project to be completed. It will take 3 to 4 weeks to complete the installation after measurements are taken. If anything goes wrong during the fabrication process, or if the top is damaged and has to be replaced, that time will be extended.
Because granite is usually sold in slabs no more than 10′ long, most countertops will require at least one seam. And since granite is sold in rectangular pieces, using seams may also reduce the costs, as in an ‘L’ shaped corner. Sometimes a seam can be placed at a sink bowl to make it less conspicuous.
Seams will always be visible in granite. Their visibility is affected by the granularity, color and pattern of the stone. Seams on a small, uniform grain or dark color will not be as noticeable as they will on a larger variegated grain or lighter color. A dramatic pattern with swaths of color will similarly highlight seams more than a uniform pattern.
Seams are always made on a straight edge. Although granite is very heavy, there could be some movement along the seam. To seal them, industry standards call for a small bead of silicone to be placed between the 2 surfaces to allow for natural expansion and contraction. This bead may be between 1/16″ and 1/8″ wide.
Individual slabs can vary slightly in their thickness. If not corrected, this would result in an uneven seam, so the installer will install shims on the underside of the top to bring the upper surfaces flush. This is considered to be the proper technique for leveling the surface. Granite may or may not be installed over plywood; the fabricator will decide that.
In most cases, some type of back splash is used. It can be the same granite used for the counters, ceramic tile, or some other product. It may be attached to the counter or to the wall, but in either case the seam between the counter and the backsplash will be sealed with caulk. The standard height for a backsplash is 4″ although they’re frequently made higher if the customer desires. Remember that the thickness of the backsplash must be considered when taking surface measurements.
Most counters are installed with a standard overhang of 1″. This may be modified to suit personal taste, but it must be stipulated before the template is made. Granite can be cantilevered up to 14″ if it’s a large piece with sufficient support on the fixed end. It should never be cantilevered where it might receive excessive stress, however, such as where someone may be tempted to sit on it or use it as a stepstool to change a light bulb. In these cases, it must always be supported. It’s always best to assume the worst and add proper support on any extension over 6″. An unsupported span of no more than 36″ is usually acceptable as long as the stone is supported on both sides of the span.
A special edge (e.g. ogee) creates an additional installation challenge where two sections of granite meet in a corner. Additional labor is required to match the two sections.
If a laminated edge is chosen using 2 cm granite, and if it’s to be mounted on frameless cabinets, or on framed cabinets that have upper retractable cutting boards, the granite will need to be raised ¾” to clear the laminated double edge that hangs down ¾”.
It is recommended that a dishwasher not be attached directly to the granite countertop, but be side-mounted to adjoining cabinets. Special brackets are available from the dishwasher manufacturer for this purpose. Drilling into the bottom of the stone can cause stress cracks and discolorations in the surface of the stone.
Preparing the site
On new construction, the base cabinets must be permanently anchored in place before a template can be made. On a remodel project, existing tops must be removed prior to measurement. Any sinks, faucets, cooktops, or any other item that requires a cutout or a hole in the top must be on site and readily available at the time the template is made. The fabricator may need to take some items with him to complete the fabrication.
Please note that any delay in acquiring the accessories may also delay the installation.
Under normal circumstances, the installer will not be responsible for connecting of dishwashers, cooktops, or plumbing.
Remember: do not make any changes to the design or specifications with the fabricator when he’s taking his measurements because those changes may affect other elements in the overall design or may result in unexpected cost increases. All changes should be arranged only through your kitchen designer.
Once the installer takes his measurements and makes the template, no changes can be made. All cuts are final; it is impossible to re-attach a piece of granite that has been cut from the slab. Additionally, once the granite is glued in place on the cabinets, moving it is very difficult and risks damaging the cabinets.
Living with Granite
Protecting the Surface
Granite is a natural stone product and has a certain degree of porosity. Therefore, after installation, it must be cleaned and sealed. Only impregnating sealers that are semi-permeable are acceptable. Impregnators do not cover up the natural beauty of the stone and do not wear off like a surface coating.
We leave a sealer kit for the homeowner to apply after construction is finished. The sealer we recommend currently is a solvent-based product that is good for three years. Re-sealing is necessary at least once every three years. Any caulk around sinks, cooktops, and seams should also be checked periodically for signs of deterioration.
Preparing the granite for sealing is an easy process. All that’s required is a thorough cleaning with mild detergent and water. Wipe off with a clean cloth and wait at least a couple of hours to let it dry completely. Examine the surface for water spots; these must be removed or sealing will make them permanent. Then simply spray on the sealer and wipe it off with a soft cloth. There is no scrubbing or buffing involved and a quart of sealant should last a lifetime.
Some food preparers have an instinctive aversion to the possibility of any chemicals coming into contact with food. While granite sealers leave only negligible surface residue and are not considered to be a health risk, those individuals may prefer to purchase a solid surface or engineered stone product that doesn’t have to be sealed.
While granite is ordinarily considered to be stain-resistant, foreign pigments or oils can be absorbed into the surface. This could cause discoloration. The sealer does not prevent this discoloration, but it slows it down to allow more time for clean up. If the top is sealed after staining, however, any foreign substance will be sealed in.
A few types of granite may show some moisture absorption if exposed for a period of time. For example, a puddle of water left on the counter for 30 minutes may show a dark spot when the water is wiped away. When allowed to dry, however, this spot will usually disappear.
Since granite was formed by extreme heat and pressure, it won’t be affected by heat from a cook top or frying pan. An open flame placed under the granite has no melting effect and will not leave any burned or scarred marks.
Granite is most susceptible to cracks during shipping and installation. Once it has been properly installed, normal use will not harm it. Because of its crystalline structure, however, it can chip if it’s subjected to blows by hard, sharp objects such as a meat cleaver. A trained professional can sometimes repair a chip with a granite dust and epoxy mixture, but no repair will be completely invisible.
Knives can be used to cut directly on the granite without harming it, but granite is harder than knife blades and will dull them very quickly. Always cut and chop on a wooden or plastic cutting board.
Keeping it Clean
Clean up generally needs only warm water and a mild liquid detergent. Abrasive cleaners such as Comet® or steel wool pads must not be used since they will scratch and dull the finish. Dulled or lightly scratched areas can be restored by using automotive rubbing compound and waxing with liquid wax.
Denatured alcohol will remove most adhesives and residue, and will not harm the finish, but acetone and lacquer thinner will damage the surface.
The main problem is oils that can be absorbed and discolor the stone, but pineapple juice may also stain it because of its acidity. If the surface appears to be discolored, a poultice is available for lifting oil stains. If it is a color stain, bleach can be used, but remember that cleaning methods must be used consistently. Do not use bleach today, and then use an ammonia based product tomorrow.
Pine Sol®, Mr. Clean®, and Turtle Wax® Foam Spray are excellent to use. Stubborn spots may be taken off by an occasional use of Soft Scrub®, but this product should be used judiciously.
Never use any product which is acidic; this includes many common liquid cleaners such as Windex. Use only sealers and cleaning products designed specifically for natural stone.
Some fabricators recommend giving the entire surface area a coat of an automotive type paste wax from time to time to help maintain appearance, but this is usually not needed.
If bacterial contamination of the kitchen countertop is a concern, granite or stainless steel are good choices according to a recent study. This study was conducted by the Hospitality Institute of Technology and Management, a St. Paul, Minnesota-based organization that develops educational materials and research for the retail food industry.
The study measured the bacteria-resistance capacity of six common countertop materials. Each surface was contaminated with E. coli (nearly 2 billion of the microorganisms), washed and rinsed with soap and water and then sanitized with a vinegar-and-water solution. The results are shown in the table below.
Dr. O. Peter Snyder Jr., who conducted the study, says, “We hope our research will help consumers make healthy decisions when selecting a countertop surface for their kitchens.”