Natural Stone FAQ
What do I need to consider when buying marble or granite?
What does “pitting” mean as it pertains to granite?
What is the typical amount of radon in granite countertops?
Are there any types of enhanced granite I should be cautious of?
What role does “rodding” play in granite countertops?
Should I use marble or granite for my kitchen countertops?
Does granite stain?
Can granite countertops stain or burn?
Can granite chip?
Can granite crack?
Can granite be repaired?
Do granite seams show?
How are seams made?
How are seams made?
Can my granite countertop be damaged?
How do I clean my granite countertops?
Does granite have any pits or fissures?
How is granite formed?
Is marble suitable for a kitchen countertop?
Where can I use marble?
Is travertine similar to limestone?
What can I expect from limestone as a building material?
How can I remove a rust stain from limestone?
Q: What do I need to consider when buying marble or granite?
A: Because it is a natural stone, marble, and more recently granite, has been blessed with a remarkable natural beauty that has captivated humans throughout the ages. Inherent in such natural products is a certain lack of predictability that sophisticated architects and designers celebrate. Consumers who are less acquainted with the material expect the marble ordered to be identical to the picture or sample they were shown. Although sample stones are intended to be representative of the quarry’s product, the material quarried at one time may differ slightly in color and veining from the sample. Moreover, even a single marble or granite slab will possess a certain amount of color variation from one end to the other. Interior designers and architects have come to view this tendency of natural stone as an advantage. Slight irregularities can be pleasing, introducing an element of the natural into human-designed spaces, whether residential or commercial.
Specifically regarding the difference between Marble & Granite, they are formed in the earth in different fashions. Granite is formed from Igneous rock (cooled molten lava). Marble is Metamorphic, which occurs from layers of minerals being compressed through the ages into stone. Because Marble is Metamorphic, it is typically softer and can contain carbon-based compounds not found in Igneous rock (carbon is burned off at 825 degrees C). This is significant, because many carbon molecules are in the form of carbonates, which can be reverted to CO2 and oxygen in the presence of acids. This is known as acid etching, and the main reason special consideration for Marble applications. Back to the top.
A: Granites are made up of many materials with differing hardness. Pits occur naturally in granite, and are a characteristic of stone. Some colors of materials have more pits that others. Biotites are quite soft and make up the black minerals in granite. Because of its softness, the first few layers are removed during the polishing process which leaves the void, or pit. The varying amounts of pits will depend on the amount of biotites, muscovite, and phlogopite in polished igneous/metamorphic rock. This does not affect the quality of the material, but instead may provide a positive or negative personal preference for the end user. Back to the top.
Q: What is the typical amount of radon in granite countertops?
A: Normally a granite countertop will emit 7.4 x 107 pCi/l of radon in the air. OK, what does that mean? Radon is a naturally occurring radioactive isotope in the earth that is continually being emitted at some level, known as the ‘background’. Some areas of the country have more background than others, hence the required testing for Radon in homes in some areas of New England to sell/buy the property. Post 9/11, all containers of material are screened for radioctivity through Customs anyway, which would prevent a ‘hot’ slab from existing. All reputable quarriers and suppliers, and fabricators who buy from them, can be rest assured they are free of any Radon beyond typical ‘background’ levels. At Capitol Granite, we have a Geologist on call to perform actual testing of slab(s) as requested by the client to clear of any potential emmissions. This is a 48 hour process, and costs approximately $250 for this service. Please contact us for more details. Back to the top.
Q: Are there any types of enhanced granite I should be cautious of?
A: Yes. Caution should be in tinting, epoxy filling, and resin filling. Tinting is a short term “fix” because eventually the color will bleed out. With epoxy (polyester) filling is sometimes used to fill Granite Dimension Stone that does not meet ASTM criteria and therefore is not suitable for wet or exterior applications. Resin filling is in granite to reduce the appearance of “pits” in granite and must be properly labeled as such so the Producer and End User are made aware. Most slabs are enhanced in today’s market with resin (prior to polishing at the producer level where the massive blocks are converted to polished slabs). Back to the top.
Q: What role does “rodding” play in granite countertops?
A: The MIA (Marble Institute of America) conducted a series of tests to verify that rodding granite countertops at the weakest point (i.e., at cutouts) will greatly reduce the amount of breakage when moving and installing the countertop. The principle is similar to putting rebar in concrete. The steel is flexible, granite is not. Rod limits tension, which stone does not like. The combination of the two is better than the individual components. Many shops down-play the importance of rodding as a safeguard for the homeowner because of the time & expense of doing it correctly. We rod all sink & cooktop front/back rails in the kitchen environment. At a minimum, rod will typically keep the piece from catastophic failure (two pieces from one) and limit the breakage to a crack that may be repaired vs replaced. Back to the top.
Q: Should I use marble or granite for my kitchen countertops?
A: Although typical application of marble is for the bathroom vanity tops, Jacuzzi tops and fireplaces, it is possible to use it in the kitchen. However, due to the fact that it is easy to scratch and is affected by acidic substances, such as vinegars, ketchups etc, we don’t usually recommend it. Moreover the high-gloss of the marble countertop can be partially lost as many chemicals etch its surface. Granite in turn is considered the second hardest stone, its polish is not subject to etching by household acids, or scratching by knives and pots and pans under normal use. It is also not affected by typical kitchen heat such as hot pans. Historically, marble has been the material of choice for centuries prior to the discovery and ability to quarry the wide variety of granites available today. Back to the top.
Q: Does granite stain?
A: In general, no. All stone, however, is porous to some extent, but Granite has very little porosity relative to other materials. Most colors will never show any moisture. A few colours may show some moisture if exposed for a period of time. For example, a puddle of water left on the counter for 30 minutes for some colors, may show a dark spot when the water is wiped away. This spot will then dry up and no evidence will show. This is an indicator you sealer needs to be re-introduced to your countertops. Back to the top.
Q: Can granite countertops stain or burn?
A: No. You can’t burn it with ordinary use. Granite is formed by extreme heat and pressure combined beneath the earths crust. It can not be affected by heat from a cook top or frying pan. A lit flame placed under the granite will have no melting effect and will not leave any burned or scarred marks. Capitol Granite recommends the use of a trivet to prevent the potential for ‘thermal shock’. This phenomenom can occur when high heat sources from a large mass are introduced to an area where the expansion/contraction creates a stress. A hot cookie sheet, or lit match does not contain enough mass, regardless of temperature. A crock pot cooking on high temp for several hours may. Back to the top.
Q: Can granite chip?
A: Only in cases of abuse , i.e. hammer / impact tool. A chip can be filled with a granite dust and epoxy mixture. Super-glue can also be used, as the clear glue will take on the appearance of the stone, and can be scraped to the same luster with a razor blade set on edge. Back to the top.
Q: Can granite crack?
A: Not typically. Granite will not crack with the ordinary use. Granite is most susceptible to cracks during shipping and installation, and when excessive force is placed on the material, like stepping on the sink rail to change a light bulb over the sink. Granite is very, very strong in compression, and normal use will not overstress this durable material. Back to the top.
Q: Can granite be repaired?
A: It is very hard to damage granite. If any damage occurs it can be sealed with a mixture of epoxy and ground up chips of granite for larger areas, or CA glue for small, minute areas. Flowable epoxies are another option for deep penetration and stabilization of ‘cracks’. Call us for more detail, if you need a repair. Back to the top.
Q: Do granite seams show?
A: Because granite is a natural material and is mined from the quarry in blocks usually no more than 10′ long, you will most likely end up with seams. Also, because granite is sold in rectangular pieces, you may want to use seams to reduce your costs, such as in an ‘L’ shaped corner. The visibility of seams will depend on the granularity, color and pattern. A small, uniform grain (such as Ubatuba) will not be as apparent as a larger varied grain (such as Typhoon Bordeaux). A dark color (Platinum) will be less apparent than a light color (Imperial White). A dramatic pattern with swaths of colour (Kinawa, Paradiso) will show more seams than a uniform pattern (Dakota Mahogany). Most customers have found that the beauty of natural granite outweighs the concern of seams. We utilize special digital photography and lay-out software to create ‘virtual seams’ to ensure veining will mate at seam locations. This is an activity we encourage the client to participate in if their material is variagated (veined), and is a service at no charge. Back to the top.
Q: How are seams made?
A: Seams are done where the two pieces of stone are put together. The seams are joined with epoxy that is mixed with the color that matches the stone. Then the joined area is smoothened, leaving only a very thin line visible. Back to the top.
Q: Can I cut on my granite countertop?
A: Only if you want to ruin your good knives. Granite is harder than your knife blades and will dull them very quickly, if you use the countertop as a cutting surface. Always cut and chop on a wooden or plastic cutting board. Back to the top.
Q: Can my granite countertop be damaged?
A: Like any solid surface, high impact blows can harm granite. Because of its crystalline structure, it can chip if subjected to sharp hard objects. Unsealed, granite can absorb stains such as oil, which can ultimately cause dark spots or discoloration. Heat from pots and pans or burning liquids will not affect granite under normal circumstances. Back to the top.
Q: How do I clean my granite countertops?
A: Polished granite is a very durable stone. It is also much harder than marble. Granite has been used in the past in the commercial industry. Some of the obvious applications have been panels on the outside of buildings, walls, and floors of “high-traffic” areas. Granite will withstand almost any element it comes up against including heat and cold. Granite itself is approximately 95-98% stain resistant but, we use a silicone impregnator on all our natural stone products. This will insure lasting life and beauty. Polished granite should receive the same cleaning care as polished marble, using a mild phosphate-free, biodegradable liquid dish-soap, soap flakes or powder which contains no aromatics. Follow with a thorough rinsing and drying with a cotton-flannel or chamois. Back to the top.
Q: Does granite have any pits or fissures?
A: Yes, granite has natural pits and fissures that are part of the stones natural structure. Some types of granite have more of such characteristics than other types, and pits can be minimized by applying sealer to the surface of the counter. Back to the top.
Q: How is granite formed?
A: Granite is an igneous rock of visible crystalline formation and texture. It is composed primarily of feldspar, quartz, and mica. It starts off as liquid magma deep within the earth’s core where it is cooled and compressed over millions of years under tons of pressure. It is the quarried, cut and polished. After that process it can be applied in various ways like kitchen countertops, vanity tops, fireplace surrounds as well as Jacuzzi surrounds and other custom designs. Back to the top.
Q: Is marble suitable for a kitchen countertop?
A: No, marble is not a practical choice for a kitchen countertop. Although it can be sealed, it is not as dense as granite and therefore it is more porous and susceptible to being stained in a highly used area like a kitchen. It is much softer and it will chip and crack under frequent use. We have, and still continue to install Marble kitchens as requested, but will educate every client, including the cleaning and maintenance of this product before we contract to perform work. Back to the top.
Q: Where can I use marble?
A: Marble can be used in a number of various applications like fireplace surrounds, tabletops, saddles, and shelves. Ideally it can be applied to a number of projects in the bath area like Jacuzzi surrounds, vanities, floor, and shower paneling. Back to the top.
Q: Is travertine similar to limestone?
A: Travertine is a type of limestone and one of the most popular natural stones for residential applications in interior and exterior wall cladding, interior and exterior paving, statuary, and curbing. Back to the top.
Q: What can I expect from limestone as a building material?
A: Color variations are inherent and are accepted as such from the quarry. However all limestone of standard architectural grade should not have any cracks or seams that would hinder the structural integrity or function of the material. Back to the top.
Q: How can I remove a rust stain from limestone?
A: Do not use acid based formulas, limestone will etch when exposed to acid. Try poultice to ‘suck’ the stain out of the material. This is safe for limestone and can also be made at home by mixing baking soda with hydrogen peroxide (stir to toothpaste consistency). Layer the area and cover with plastic wrap for 24 hours then remove. You may need to repeat or if comfortable consider using steel wool to lightly sand out the rust. Back to the top.