Is My Countertop Quartzite or Marble?
In recent years, there have been complaints from consumers who thought they had purchased quartzite for their countertops because of their its unique durability. Quartzite will not etch (a dullness of the surface) or become easily scratched. Later, when their tops are etched and scratched, they learn the hard way that their tops are actually marble. Marble is a beautiful stone and in the right environment an ideal choice. But for kitchens and other places where the countertops are exposed to high use and acidic liquids, without being specially protected, marble will become damaged and will need to be professionally honed and polished to restore that brand new look. This article explains the difference between quartzite and marble and how to tell what countertop material you truly have
About Marble
Marble is a metamorphic material that contains an abundance of the mineral calcium carbonate, which is soft and chemically reacts to acidic substances. This means marble is very susceptible to acid etch damage. Heat, pressure, and other geological forces destroy or modify the texture and structure of limestone or dolomite rock, resulting in a new form of rock known as marble. When the limestone or dolomite are very pure, the resulting marble is white. When the limestone or dolomite is mixed with clay, iron oxides, or other minerals, the resulting marble may have swirls, veins, or varieties in color.
About Quartzite
Quartzite is also a metamorphic rock but differs from marble in that it does not contain calcium carbonate. This means it is not susceptible to acid etch damage. Quartzite is formed when heat, pressure, and other geological forces destroy or modify the texture and structure of quartz sandstone. When the quartz sandstone is very pure, the resulting quartzite is white or gray. When the quartz is mixed with iron oxide or other minerals, the resulting quartzite may have streaks, lenses (transparent pieces), and varieties color.
Tests to Determine Stone Type: Marble or Quartzite
Marble and quartzite can be very similar in appearance. Fortunately, there are a couple of simple tests one can perform to tell the difference between them: the scratch test and the acid test. If you attempt to perform either of these potentially destructive tests, you should obtain a sample or use a piece of scrap countertop material to perform the tests. If neither are available to you, test in an inconspicuous spot knowing that the test may cause damage.
The Scratch Test
In order to understand how the scratch test works, we need to provide a little more science. The hardness of minerals can be determined by what is called the Mohs scale of mineral hardness. This scale rates minerals from the softest mineral, being a 1, to the hardest mineral, being a 10. Calcium has a Mohs hardness of 3. Quartz has a hardness of 7. A standard kitchen knife has a hardness of about 6.
Use a knife to scratch the surface of a countertop. The outcome indicates the hardness of the mineral. If the knife leaves a scratch, the stone is likely marble. If there are no scratches, the stone is likely a much harder stone like quartzite or granite.
The Acid Test
Calcium reacts to acids, causing etch damage. The etch may or may not have texture, depending on the severity of etch damage. Common acids will not affect quartz. Vinegar or a lemon wedge can be used for the test. Place the lemon wedge or a drop or two of vinegar on the stone and allow several minutes dwell time. Wipe up the excess. If it leaves a dull spot, that a positive indication for the presences of calcium, which indicates the countertop is marble and not quartzite.
What You Need to Know If You Have Marble
If you discovered you have marble, not quartzite, by way of these tests or because you already have countertops installed that have etch marks or scratches, rest assured that you are not doomed to live with unsightly damage or replace your countertops. Professional stone restoration contractors can hone and polish your countertops, virtually erasing damage and leaving your tops with a beautiful, pristine finish. Your contractor can also offer solutions for protection appropriate for your countertop material.
This article, written by Fred Hueston, Chief Technical Director of Surface Care PROS, and president of Stone Forensics, is one of a series of articles written and published on behalf of Surface Care PRO Partners.
FAQs
One way to distinguish a quartzite slab form a marble one is to perform a scratch test. Since these two materials differ in hardness, using a piece of the stone to 'scratch' a material that is harder thanmarble but softer than quartzite will reveal which stone you have.
How to tell the difference between marble and quartzite? ›
One of the biggest differences between these two natural stones is their hardness — quartzite countertops are much harder than marble countertops. This hardness plays a role in how porous the surfaces are, which is a major factor to consider when selecting your kitchen countertops.
How do I tell what material my countertop is made of? ›
Use a knife to scratch the surface of a countertop. The outcome indicates the hardness of the mineral. If the knife leaves a scratch, the stone is likely marble. If there are no scratches, the stone is likely a much harder stone like quartzite or granite.
How do I know if my countertop is quartz or quartzite? ›
Despite sounding like similar surfaces, quartz and quartzite are different and distinct materials: quartz is a manmade, engineered surface, and quartzite is a natural stone mined from quarries all over the world.
What test could you perform to distinguish quartzite from marble? ›
Hardness Testing
This is perhaps the easiest test available. If you take a piece of glass to a piece of marble, a scratch will be left on the piece of stone. Do the same with quartzite. You'll notice that no scratch will be left on the surface due to its harder properties.
How can you identify quartzite? ›
Quartzite is a hard, nonfoliated metamorphic rock formed by the action of heat and pressure upon sandstone. Usually, the rock is white or gray, but it occurs in other pale colors. It has a grainy, rough surface. Magnification reveals a mosaic of quartz crystals.
What does quartzite look like? ›
Appearance: Pure quartzite is usually white to gray, though quartzite often occurs in various shades of pink and red due to varying amounts of iron oxide (Fe2O3). Other colors, such as yellow and orange, are due to other mineral impurities.
Is man-made marble cheaper? ›
Generally speaking, cultured marble countertops can be had for half or third of the price of quarried natural stones. With little visual difference and tougher durability, cultured marble is a top pick for interior designers and homeowners, alike.
What are fake countertops made of? ›
Like other Like other laminate countertops, Formica kitchen countertops are made from layers of plastic, bonded to kraft paper or particleboard to create a solid, durable countertop surface., Formica kitchen countertops are made from layers of plastic, bonded to kraft paper or particleboard to create a solid, durable ...
What is the easiest way to identify marble? ›
If you are trying to determine if what you're looking at is real marble, check for scratches or wear. If you scratch a knife across an area on the underside of the stone or in an area that will not be seen and you don't see much damage, then the stone is likely man-made marble or granite.
At the other end of the spectrum, Calacatta marble is one of the most expensive natural stones on the market. Quartzite is more moderately priced but still might be considered a luxury for some homeowners.
Does quartz really look like marble? ›
So, while marble may have odd pigments or colors, or a marble slab may have veining or colors you don't care for, quartz slabs will always have a consistent veining and color that you can count on. This includes quartz that looks like Carrara marble or Calacatta marble – two of the most popular marble colors.
How do you test for quartzite? ›
Use the tip of the knife blade to try to scratch the stone. If it's real quartzite it will only scratch lightly or not at all. An etch test can also be completed. Placing vinegar or lemon juice on the surface of the slab for about 15 minutes will reveal if the stone is real quartzite.
What is the downside to quartzite? ›
While its density makes it hard and durable, it also makes quartzite very heavy. Due to its weight and hardness, quartzite is more challenging to install. Since it requires specialized tools and training, installing quartzite is a major hassle compared to most other materials.
Does quartzite have visible crystals? ›
Texture - granular. Grain size - medium grained; can see interlocking quartz crystals with the naked eye.
What is more expensive, quartzite or marble? ›
For example, Calacatta Vagli marble is approximately $180 per square foot while Carrara marble is around $40 per square foot. Quartzite countertops average between $60 and $100 per square foot, although this may go higher if you choose a more exotic type of stone or design.
How could mineral hardness be used to tell quartzite from marble? ›
Marble is soft; quartzite is hard.
It's easy to get a sense for a stone's hardness by trying to scratch it with a common material like a copper penny or steel knife blade. Marble is made of calcite, which has a hardness of 3 on Mohs hardness scale.
How can you distinguish between similar looking metamorphic rocks marble and quartzite? ›
Marble and quartzite often look similar, but these minerals are considerably softer than quartz. Another way to distinguish marble from quartzite is with a drop of dilute hydrochloric acid. Marble will effervesce (fizz) if it is made of calcite.
What identifies quartzite? ›
Quartzite is a very hard stone. This is one of the key ways to separate quartzite identification from its imposters. On the Mohs Hardness Scale of 1-10 with one being talc and ten being diamond, quartzite rates as a seven. This means that it's harder than the blade of a knife and harder than glass.
