Homeowners looking for a natural stone for their kitchen countertops that offers the look of marble, but the durability of granite, will be happy to know that there are several varieties of quartzite that perfectly fit the bill.

From Sandstone to Quartzite 

To nip any confusion in the bud, quartzite is a naturally occurring stone mainly comprised of natural quartz from sand that has crystallized under immense pressure and heat far below the Earth’s surface. It’s actually made up of the same basic elements as sandstone, except pressure and heat transformed the sandstone into quartzite by pushing the granules of sand together so tightly that they melded together.

The Difference Between Quartz and Quartzite

The man made product, confusingly named Quartz, is made of granite particles and polymers. Don’t confuse natural quartzite with Quartz, or other similar man made products. They are different products that require different levels of care and treatment.

Quartzite, Granite, and Marble Differences

While quartzite can look similar to granite and marble there are very distinct differences. The most important difference is the relative hardness of the stone. Marble is soft, relative to quartzite, and it is prone to etches, stains, and damage from other mishaps. Quartzite, on the other hand, is extremely hard and durable. It’s even harder than granite; that is if the stone is truly quartzite. Sometimes stone sellers will label certain types of sandstone as quartzite. If durability is the characteristic a person is seeking out for his or her countertop, it pays to ask about the hardness of the stone.

Quartzite Hardness and Wear Resistance 

Kitchens that get a lot of wear and tear are probably going to stay nice-looking longer if the countertop is made of a harder stone, unless the owner of the kitchen is extremely meticulous about coasters, wiping spills immediately, and avoiding slip-ups like dropping a pan or sharp knife, or sliding a glass dish across the stone’s surface without a cloth underneath. Quartzite happens to be even harder than glass, meaning that it will scratch glass, rather than the other way around. Marble, on the other hand, will scratch from glass.

There’s a scale called the MOHS Hardness Scale and quartzite should get a score of 7 or higher. Granite is typically a 6 on the scale, while marble checks in at a 3. To be clear, however, all of the stones are hard enough to make great countertops, even marble. Softer stones simply need more care and proper sealing to stay beautiful through years of heavy use.

Quartzite Porosity 

While all quartzites are hard on the MOHS scale, and resistant to etching from acids like lemon juice, that doesn’t mean they are all the same when it comes to countertop care. Some quartzites are more porous, meaning they will readily absorb water. Porous stones are more susceptible to stains and watermarks. It’s important that homeowners and fabricators understand what type of stone they are dealing with so that they apply sealants properly and care for the stone correctly over time. 

There are very simple tests fabricators and homeowners can conduct themselves to assess porosity. They can simply pour a little water on the stone and count the time it takes for the water to absorb, or take a sample of the stone and set it in water to see how far the water wicks up the stone. A porous stone will absorb more water, while some of the most non-porous quartzites will not absorb any water at all. 

The Colors of Quartzite 

Appearance-wise, most quartzite is white with light to heavy patches of gray which, in many cases, gives it a marble-like appearance. Quartzites such as Super White, Sea Pearl and Mont Blanc are mostly white and gray. Some have different striations of gray that give them a slightly different appearance, but the overall look and feel is reminiscent of marble.

Depending on what elements were present when the quartzite formed, other colors may also appear or dominate. Taj Mahal, for example, is primarily white with veins of cream, beige or taupe. It also brings to mind the feel of marble, but with the warmer tones of beige instead of gray. Taj Mahal is also one of the most durable and non-porous quartzites available, which makes it extremely popular for homeowners who love to cook but loathe too much fuss.

Quartzites that boast different bold colors, such as Midnight Fusion, Blue Louise, and Van Gogh are actually mixtures of quartzite with other minerals. Each slab may vary in porosity from one to the next, but they should all be hard and durable.

Dense Sandstone or True Quartzite?

Because quartzite comes from sandstone, there is a lot of confusion about whether a particular stone is actually sandstone or quartzite, especially among the more porous quartzites on the market. The fact is that some stones labeled as quartzite aren’t technically quartzite; they are dense sandstones. Sellers are trying to play tricks. They are all still beautiful and durable, and just as hard on the Mohs Scale (meaning acids will not etch them and glass will not scratch). 

The big, and important difference is that they are more porous because the grains of sand that make up the material are not fused together as tightly as true quartzites. Some popular quartzites that technically fall into the category of “dense sandstones” are Wild Sea, White Sea and Lavender Grey. A close look at the stone with a magnifying glass will reveal individual sand grains.

Many of the most popular quartzites on the market are just one step above dense sandstone and these are technically “intermediate” or “grainy” quartzites. Mont Blanc, White Macaubus, Infinity White and many others fall into this category. Intermediate quartzites are differentiated by visible cross bedding. Cross bedding is responsible for some of the distinct, repeating lines of color that give the stone its unique character. Such cross bedding is caused by prevailing river currents or winds that were present at the time when the stone was forming deep beneath the earth. 

A few sand grains may also be visible within the stone. Intermediate quartzites are naturally more porous than fully formed quartzites so it is important that fabricators, or homeowners applying their own sealant, test the porosity to make sure the correct amount of sealant is applied to protect the stone from stains.

The least porous quartzites are technically called crystalline quartzite. They have undergone such immense heat and pressure, that there are no sand grains or cross bedding patterns visible any longer. The sand grains have actually been pressed together so hard that they become crystals of quartz. All the quartz crystals combine together in a single stone to become quartzite. Taj Mahal and Sea Pearl are two examples of popular quartzites that are really and truly 100 percent quartzite, not something in-between sandstone and quartzite.

Is Quartzite a Good Choice for You?

Whether a homeowner ends up with dense sandstone or true quartzite, or even marble, is not significant in terms of the value of the kitchen per se. The most important consideration is how the stone fits the buyer’s aesthetic and lifestyle. For a family with a bunch of kids spilling grape juice and lemonade on a daily basis, a soft and porous stone might not be the best choice. Quartzite is an excellent alternative to marble in such cases, but buyers need to remember to make sure their stone is sealed properly if they choose a quartzite that is not technically a crystalline quartzite. 

 

Sources:
https://usenaturalstone.org/definitive-guide-quartzite/
https://usenaturalstone.org/properties-of-quartzite/