Quartzite vs Sandstone: Comparatively Similar & Different

As the title suggests, comparing the natural stones quartzite and sandstone gives you all kinds of interesting and informative details. It just depends on how deep you are willing to dive in your comparison. For example, just looking at the label and taking that as the complete picture might leave you thinking that your surface is one type of stone when geologically speaking, it is really another kind of stone altogether. And, merely viewing the surface superficially, could yield the same outcome. The fact is, natural quartzite and natural sandstone are very similar for very good reason. Yet, they are also classified as different stones geologically. In this article we will, without turning it into a dissertation on these materials, simply explain why these materials are comparitively similar & different. So if you are up for taking the next few minutes to read about these natural stone countertop materials, settle in as we consider quartzite vs sandstone and how these materials compare.

Natural Sandstone Is, Well, Sand

It may sound obvious, but with all the creative naming methods used these days for architectural and building materials, being specific is practical. So in considering what sandstone is, we need to begin by defining what we mean by the term sandstone. The material we are speaking of here is the sedimentary rock. geology.com defines it this way:

Sandstone is a sedimentary rock composed of sand-size grains of mineral, rock, or organic material. It also contains a cementing material that binds the sand grains together and may contain a matrix of silt- or clay-size particles that occupy the spaces between the sand grains.

So it is a stone that is made up largely of sand, which is in many cases composed of... wait for it... quartz. That's right, sandstone contains a good deal of the mineral quartz. You can probably tell where this is ultimately leading, but we'll continue anyway. Sandstone varies in the density, porosity, and even color. But there comes a point when the forces that operate on sandstone change this beautiful rock into a different material altogether. And that leads us to the next subheading; quartzite.

Quartzite Is, Well, Quartz

This too may sound obvious, yet it is the case. And just as we said regarding names being challenging to decipher, the same is true for quartzite; if not more so than for sandstone. If you remember, earlier we said that sandstone is composed mainly of sand. And we also said that sand is usually made up of the mineral quartz. Therefore, quartzite is virtually all quartz. Hence the name, quartzite. You may be asking at this point, "What makes it different than sandstone?" Well, quartzite is actually a metamorphic rock that was previously sandstone. Geologist Karen Kirk in an article she wrote on usenaturalstone.org described it this way:

Quartzite picks up where sandstone leaves off. It's a metamorphic rock - one that's been baked into an extra-tough stone by the heat and pressure that only comes from deep burial way down in Earth's crust. Such events are usually brought about by tectonic collisions, where continents grind into each other.

Quartzite isn't melted sandstone. It's sandstone that is fused together so tightly that the sand grains lose their individual identities. The minerals crystallize together into a dense fabric of quartz crystals. The deeper and hotter the stone gets, the more tightly it's fused.

So it sound clear cut right? Well, no so much. Karen goes on to say this:

Here is the key point: The heat and pressure that turn sandstone to quartzite is not a definitive, black-and-white occurrence. It's a gradual process, with subtle differences occurring all along the spectrum. There is no exact moment that sandstone becomes quartzite. It's similar to the way that colors blend from one shade to the next. When does Royal Blue become Navy Blue? It's hard to pin down, exactly. Because there is a range of quartzites and sandstones, it's wise to assess each stone as an individual, rather than relying on broad categories or stone names as the last word on how a given stone will behave.

So, you can see why this article is entitled: Quartzite vs Sandstone: Comparatively Similar & Different! They are similar because one starts out as the other and they are different because after the change happens, they are no longer the same structurally speaking.

Similarities Between Sandstone and Quartzite

As you may have concluded from our discussion up to now, the similarities between quartzite and sandstone stem from the mineral content. They both contain high amounts of quartz (which is not the same as the countertop surface material). For a comparison with that material, check out our article entitled: Differences Between Quartz & Quartzite.

By reading the explanation cited above you might be inclined to think that quartzite and sandstone are dissimilar in how hard they are. But notice that she stated "There is no exact moment that sandstone becomes quartzite." And then she goes on to explain that the process is so gradual that it can be difficult to distinguish on e from the other. Why? Because there are sandstones that are so compressed and heated that have the properties of quartzite even though they technically are not, geologically speaking. So, if you think of sandstone as being on the left end of a spectrum and quartzite as being on the right end of the same spectrum, we are talking about points near the middle of that spectrum. Some quartzites near the middle, will look very much like some sandstones near the middle, and they will be... you guessed it... similar even though they are two different stones.

Sandstone and Quartzite Differences

So what about the differences? If these materials are similar how in the world can they be two different materials? Well, let's go back to the example of the spectrum. Now imagine that you have a sandstone slab that is out toward the left end of the spectrum and a quartzite slab that is way out toward the right end. In other words, you have one stone that is very, very quartzite. And you the other is very, very, sandstone. Those are the two stones that will be different. The sandstone will not be as hard as the quartzsite. The quartzite slab will be less porous that the sandstone. And the texture will feel different as well.

So if at the beginning of this article you were wondering how it is possible that two stones could be similar and different, we hope we have helped clarify it for you. It all depends on the two stones you are comparing. It also depends largely on where in that imaginary spectrum between sandstone and quartzite each of those stones are. What is the lesson then? Be sure to find out the the stone's hardness, porosity, and mineral content to be sure you know what you really are getting. And try not to think of a slab in terms of the label it has been given. Because some sandstone is as hard as some quartzite and not very porous. And by the same token, some quartzite is not as hard as other quartzite. In the end, get the stone you will be satisfied with.