Content provided by GK’s Custom Polishing
Natural stone countertops have become increasingly popular over the years due to their elegance and durability. Although marble and granite are by far the most popular, quartzite (natural stone) and quartz (man-made material) have been increasing in popularity. Since each type of countertop material is made up of different minerals, each type also has different maintenance requirements. Knowing the makeup of each countertop material and the maintenance that will be required after it is installed in your home will help you choose the countertop material that is best for you.
- Granite is a natural stone. It is a very hard igneous rock containing quartz, mica and feldspar as its main mineral makeup.
- According to Moh’s Scale of Mineral Hardness, granite is typically a 6-8 on the scale (1 is the softest and 10 is the hardest). For reference, your fingernail is a 3 and a steel knife is a 7 on the hardness scale. Since granite is a harder natural stone, you do not have to take as many precautions with it and it does not require as much maintenance as marble or softer natural stones.
- Granite does not contain the mineral Calcite like marble, limestone and travertine. The mineral Calcite is what harshly reacts to contact with acids and creates etch marks on the surface of a natural stone.
- Granite is a porous material, which means it can allow for the transfer of liquids through the material. Because of this, granite should be sealed with an impregnating (penetrating) sealer. Depending on the location of the granite (kitchen countertop, exterior surface, shower, etc.…), the specific variety of granite (which is important to determine the hardness and porosity of the granite) and the quality of sealer that is applied – granite will need to be re-sealed periodically. Often times, 3-5 years for re-sealing a granite surface is a good rule to follow, but it could be more often if the granite is exposed to the outside elements or sees higher usage. It could need sealed less often if a higher quality sealer is used or the granite sees minimal usage.
- Granite typically starts to show signs of wear (larger scratches or many smaller scratches that make the granite appear dull), about 5-15 years after it is installed (depending on the variety). This is an average. Depending on the hardness of the granite, where the granite is located and the usage of the granite will determine the exact timeframe. When granite does began to dull, it can be refinished using diamond abrasives to look like new.
- DO NOT CUT directly on granite and DO NOT PUT HOT PANS directly on granite. Granite is a very hard and durable natural stone, but even the hardest things are not completely impervious to scratches and wear. Most granite surfaces will not show signs of wear right away if you cut or put a hot pan directly on the surface. Over time (could be a couple of times or it could take hundreds of times), cutting directly on granite will start to scratch the surface of the stone. Also, depending on the temperature of the granite and how hot a pan is that comes in contact with it, the difference in temperature can POP or fracture the minerals in the stone. This will create a crack or pit in the granite.
- Marble is a natural stone. It is a softer rock that is comprised of metamorphosed limestone, containing mostly recrystallized calcite or dolomite.
- According to Moh’s Scale of Mineral Hardness, marble is typically a 3-5 on the scale (1 is the softest and 10 is the hardest). Due to the softness of marble, it can scratch relatively easy. The biggest cause of scratches in countertops is dragging pots, pans, plate or cups across the surface.
- Since one of the main minerals in most marble varieties is Calcite, it is reactive when it comes in contact with something acidic. When something acidic comes in contact with the marble (tomatoes, lemons, soda, perfume, toothpaste, hairspray, etc…), a chemical reaction between the acid and the Calcite in the marble begins. This chemical reaction heats up the surface of the stone and actually burns the top layer of stone, creating a dull spot (or etch mark). The stronger the acid, the deeper and more pronounced the etch mark will be. The only way to remove etch marks is to hone them out with diamond abrasives and then re-polish the surface.
- Just like granite, marble is a porous material. It should be re-sealed periodically (see #4 above in the granite facts section).
- Marble wears at different rates. Due to it being softer than granite, it will wear faster than granite. The key to keeping marble in good condition on a countertop is to monitor anything that comes in contact with the surface. Acids create etch marks and rough/sharp objects create scratches. Use cutting boards, trivets, immediately wipe up spills and always make sure your countertops are dusted to remove little pieces of grit that can cause scratches. Most marble surfaces can be restored to like new condition, but taking care of marble requires extra precautions by the homeowner and will require professional maintenance more frequently than other countertop surfaces.
Engineered Quartz Facts
- Engineered quartz is a countertop material that is man-made. It is comprised of about 90% quartz (ground-up) that is bonded together with about 10% resins, polymers and pigments.
- According to Moh’s Scale of Mineral Hardness, engineered quartz is typically a 7 on the scale (1 is the softest and 10 is the hardest).
- Since engineered quartz is mostly made up of the mineral quartz (with some resins holding everything together) it is just as hard (and sometimes harder), than granite.
- Engineered quartz, for the most part, is a non-porous material. This type of countertop surface typically doesn’t require sealing.
- Although engineered quartz is very hard, non-porous and requires very little maintenance, it can still scratch and is not completely resistant to wear. NO SURFACE is completely indestructible. If you cut directly on engineered quartz or put a hot pan directly on the surface, you can cause damage just like any other countertop surface.
- Although it is rare, we have seen engineered quartz countertops with scratches and wear in the surface. If this happens, there may not be a way to completely refinish the surface back to its original factory condition (assuming the original finish is a highly polished finish). Removing the scratches can be done, re-creating a consistent finish is possible, but creating a high polish is extremely difficult with an engineered quartz countertop. The amount of heat that is required to polish the quartz mineral in the countertop will actually melt the resin that bonds everything together.
- Quartzite (which contains at least 90% quartz) is becoming more popular for countertops. Quartzite actually starts off as sandstone and is transformed into a much harder stone after being subjected to high heat and pressure for many years (usually thousands of years).
- According to Moh’s Scale of Mineral Hardness, quartzite is typically an 8 on the scale (1 is the softest and 10 is the hardest).
- Quartzite is very similar to granite (since granite too contains quartz at a lower percentage), but quartzite is usually even harder and more scratch-resistant than granite. Quartzite will not etch when it comes in contact with acids.
- Quartzite should be sealed and maintained similarly to granite because it is very similar to the hardest granite varieties (see #4, #5 and #6 above in the granite facts section).
- Although quartzite countertops are as hard as granite and much harder than marble, we have seen many quartzite slabs that contain Calcite. This means they are reactive to acids and will etch like marble. If the natural stone is white or lighter color, it is very possible that the surface contains Calcite and will etch.
Even if you are an expert in the natural stone industry, it is still possible to get stumped on the makeup of a specific type of natural stone. There are thousands of natural stone varieties in the world. We have seen times where a granite is sold as a granite, but in reality it ends up being a different type of material. Please spend plenty of time researching the material – so you are not disappointed with the final outcome.
Because of the information above, we ALWAYS recommend to customers that they do samples on the actual slab they will be purchasing for their countertop project (not a slab that is similar to your slab because every slab varies). The most important test is to see if it reacts to acids, which means it is marble (or a Calcite based stone) and will be more difficult to maintain. Other tests would be scratch and stain tests to determine how hard and porous the countertop material is.
If you are not sure how to best care for your natural stone floors or countertops, feel free to consult with the experts at GK’s Custom Polishing, Inc. We are Cleveland’s headquarters for commercial and residential hard surface maintenance. We offer professional cleaning, restoration and sealing for natural stone, concrete and ceramic tile and grout. Give us a call at (440) 937-4457 or send us an email to get a free estimate.