All granites are naturally occurring igneous rocks made up of minerals. In the case of countertop granite, the primary mineral constituent is quartz. This mineral is extremely hard and accounts for approximately 50% of its makeup. Remaining minerals include feldspar, mica, amphibole, and trace minerals.
The main color categories for granite countertops include beige, black, blue, brown, burgundy, gray, green, red, yellow, and white (also referred to as white and black). Interestingly, although granite is primarily made of the mineral quartz (which is typically white), it's the non-quartz minerals that are responsible for its many thousands of colors, textures, and veining (see image below).
Color and textural variations within granite countertops are grouped into "grades" or "levels." A grade of 1 means that you are dealing with a granite that has the simplest and most repeatable coloration and texture. Higher grades indicate increasingly more unique colors and textures. Grades 1 and 2 are typically used in home kitchens and bathrooms. Businesses regularly use grades 3 to 7. As a rule. as the level increases, so does its price per square foot.
First off, the term "quartz" in a countertop context actually refers to a manufactured mixture that contains crushed quartz (called quartz aggregate), along with polymers, resins, and pigments. The proper name for a quartz countertop is "engineered quartz."
The composition of engineered quartz is typically described by the weight percentage of its materials - specifically 93% aggregated quartz and 7% polymers, resins and pigment. However, since quartz aggregate is so dense, and the final mixture depends so heavily upon lightweight polymers, it's much better to visualize the mixture by volume percent. Using this approach the composition is 66% quartz aggregate and 34% polymer/resin/pigment. The point here is that although both countertop materials have similar weights as final products, lightweight polymers are critical to the makeup of engineered quartz.
Interestingly, the smallest fraction of engineered quartz (its pigments) plays a key role in its appearance. This is because the pigments allow engineered quartz to approximate some of the textures and colorations of grade 1 and 2 granites. Without pigments, engineered quartz would only be available in an off-white coloration.
Engineered quartz countertops are made by mixing quartz aggregate powders, polyester resins, and pigments and injecting them into vibro-compression vacuum molding machines. Over time, the resins sufficiently bind together with the quartz aggregate particles and become finished slabs. The flow diagram below shows the entire manufacturing process (pinch it wider if you are using a mobile device or 2-in-1 device).
The current price of grades 1 and 2 granite counters ranges between $30.00 and $50.00 per square foot installed. However, for all durable countertops this does not include a separate fee charged for base counter measuring (also called templating). This fee ranges from $200.00 to $400.00 and is often listed separately because the work is routinely conducted by an independent specialist. Templating enables your fabricator/installer to accurately cut and edge your chosen slab.
Most homeowners prefer grades 1 and 2 granite because they are quite affordable and match many kitchen and bathroom color schemes. As was mentioned previously, commercial projects tend to use higher grades of granite for their counters. However, because grades 3-7 have increasingly unique colorations, textures, and veining, they are pricey. They start at $60.00 per square foot installed.
Based on the popularity of grades 1 and 2 granite, engineered quartz has successfully engineered pigment formulations that approximate the appearance of these granite grades. As for comparative pricing, expect to pay 15-30% more installed for quartz versus level 1 or 2 granite.
The video below shows two different granite countertop samples heated to 450 degrees F for one hour (granite melts around 2300 degrees F). After both are removed from the oven, water is poured over them (which explosively boils), and no thermal shock cracking occurs. Next, the host attempts to locally heat each sample using a propane torch. In both cases, the samples are completely unaffected. This is typical of all forms of granite.
In comparison, engineered quartz countertops do not handle rapid temperature changes nearly as well as granite counters. Pots, pans and other objects between 200 and 300 degrees F should never be placed directly onto an engineered quartz surface without a heat barrier underneath. Otherwise, the surface could be permanently damaged.
Since engineered quartz requires a large volume of polymers to bind its quartz aggregate together (see composition and manufacturing sections above) the impact of direct flame exposure on this material is important to understand. However, most quartz countertop manufacturers do not disclose flame resistance information. Since we sell both products, we decided to show you a video (below) comparing the flame resistance of quartz and granite countertop materials. As is evident, engineered quartz supports combustion over time while granite does not.
Many dedicated quartz countertop suppliers argue that engineered quartz is a "green material" with a low carbon footprint while granite is not. Since convoluted marketing arguments are used to reach this conclusion, we thought it was worth a brief discussion.
First off, granite is a completely natural material quarried from the earth, while engineered quartz is mixture of aggregated quartz particles and polymers that are "bound together" using specialized vacuum molding machines. This fact alone makes it quite clear that granite is the obvious winner. In any event, since one would never discard engineered quartz or granite without negatively impacting the environment, we think that this entire argument should be left at, "both are excellent durable countertop materials."
With lighter or brighter colored quartz countertops, seams can be more visible than with granite. In addition, because engineered quartz contains a large quantity of polymers and resins, it has a tendency to twist over time. This is because its polymer binder continues to cure over time. Thus, it's important to make sure that a quartz counter is firmly affixed to the counter base and that all seams are located strategically away from areas of stress. You can't always avoid seams, but you can minimize them by optimizing access to the installation site and fabricating the countertop with care.
The large volume of polymers in engineered quartz makes it nearly non-porous. This is a positive attribute because it makes bacterial growth less likely. Quarried granite is slightly porous. To compensate for this, it's standard practice to add a surface sealer to granite once it has been installed. Once applied (which is a simple “wipe on and let dry” process), granite also becomes non-porous. Thus, both materials have minimal porosity once installed..
Note: Due to the availability of newer sealants, most granite countertops only need to be resealed every 15 years. Newer sealants dry on very hard. This enables them to last longer and protect better.
Both engineered quartz and granite are extremely hard materials that excel as durable countertops. Engineered quartz has a Moh's scale of hardness value of 7. Granite comes in at a 6. Since utensil steel has a hardness value of 5, there's no difference in scratch resistance between either quartz or granite countertops. You should never use countertop surfaces as cutting boards anyway.
As long as you use rounded or "radiused" edges on countertops (versus sharp 90° edges), then chipping of quartz or granite is highly unlikely. However, should a chip occur, both counters can be repaired in most cases.
Strong chemicals like dyes, bleaches, and many solvents can permanently discolor engineered quartz. This is because its high polymer content makes it reactive to more materials. For example, you should never clean quartz using bleach, oil soaps, or topical liquids. Such chemicals will degrade its surface finish and can result in permanent surface damage. This is not much of a concern with granite. Even if a material somehow dulls a granite sealant by reacting with it, you can always reapply more sealant.
Although UV inhibitors are added to engineered quartz during the manufacturing process, the polymers in this material will degrade with continued exposure to ultraviolet light. This results in color fading, potential warping, and strength reduction. As a result, engineered quartz counters are not recommended for outdoor use. In contrast, granite countertops are excellent for both indoor and outdoor use.
Good question. If you prefer very light or unusual colors, then you'll may like some varieties of engineered quartz. Many ultra-modern kitchen designs tend to work well with some of the more unique colors available with engineered quartz. However, if you prefer the colors, 3D depth of coloration, and the textures of granite, then quartz may not be your ideal choice. Granite can also save you some money when compared to similar colors and textures of quartz.
In the end, the choice is yours. If you want to see what might be best for you, then why not try out our virtual kitchen design tool for choosing granite and quartz countertops? With it, you can vary cabinet color/type, flooring and backsplash designs in order to pick your ideal countertop!
On average, granite and quartz countertops will add between two to three times their installed cost to your home’s value. Since kitchens and bathrooms are the most important rooms for increasing home value, choosing the best durable countertops for these areas is always a wise decision. If taken care of properly, both granite and quartz countertops will likely last well over 20 years.