Quartzite vs Limestone

When considering what material to use for hard surfaces in construction projects, it is good to consider two of the natural stone types that may be not as well known as other materials by consumers and fabrication professionals with relatively less experience than other hard surface materials. In this article we will take a look at quartzite vs limestone. During the consideration we will compare the properties of these materials. Additionally, we will explore some things to be mindful of when working with each. Finally, we will take a look at what goes into caring for and maintaining each of these materials.

What is Quartzite

Natural quartzite is a metamorphic rock that is the result of intense pressure and heat being applied to sandstone. For this reason quartzite is composed of the same minerals that make up sandstone. We won't go into the details of what the minerals are in the sense of the chemical formulae. But to put it simply, natural quartzite, as its name implies is made up completely of quartz. And that makes sense because sandstone is formed from sand and it too is made up of a mixture of silicates; one of which is quartz. So ot summarize, quartzite is a natural stone that used to be sandstone and is primarily composed of quartz.

What is Limestone?

While quartzite is a metaporphic rock which used to be a sedimentary stone, limestone is a sedimentary stone from which another metamorphic rock is made. Limestone is primarily made up of calcite (calcium carbonate). It often forms in aquatic environments. Calcium carbonate from the debris of marine life such as oysters, clams, mussels, and coral organisms settle to the bottom of the ocean. Pressure and chemical changes in the material then lithify the substance and thus limestone comes to be. So to put it simply, limestone is natural stone that forms in aquatic environments that is mainly composed of calcium carbonate.

Comparing Properties

Any time hard surface materials are compared, it involves the properties of the materials under consideration. Therefor we need to know what the properties of quartzite and limestone are so we can make the comparison.

In the descriptions of each of these natural stone materials above, we mentioned the substances that compose the stone. This is because the materials that make up these stones contribute to the properties through which the comparison is made.

Comparing Hardness

The hardness of surfaces are measured using the Mohs scale of mineral hardness. This scale ranges from 1 to 10 and each material lies somewhere on that scale. What about our considering quartzite vs limestone? Well, quartzite, being composed mainly of quartz (a hard mineral), registers at 7. On the other hand, limestone, being composed of calcite (a relatively soft mineral), registers in the 3 to 4 range. So we have one soft stone and on hard stone.

The hardness of a stone contributes to the durability of it in the sense that hard stone is more difficult to scratch. Scratch resistance is an important factor to consider when selecting a material for a surface.in some cases, the hard material is the best and in others either material will be hard enough.

Porosity Comparison

Most natural stone is porous. The prosity of each slab of natural stone will vary to one degree or another. Stone suppliers may offer more than one grade of material and it is a good idea to inquire of differences in porosity. Generally, quartzite is less porous than limestone because of the composition of each. However, there are techniques to counteracting negative effects of porosity. We will consider those later.

How Colors Compare

Like other properties of natural stone, the composition of these materials affects the color(s) of the resulting slabs. Since calcium carbonate is a very light colored material, it stands to reason that limestone (which is made up of calcite) is a light color. White, cream, beige, tan, and gray are all colors in which limestone forms. Similarly, quartzite is, as we mentioned above, transformed from sandstone and most sand is also a light color. So quartzite too may be found in a variety of light colors with hues similar to that of limestone. However, quartzite can also have other minerals that are made up of quartz and are other colors. So you will often times see quartzite slabs with a broad range of colors. Quartzite slabs then may have virtually any color in them. Again, there are uses for each kind of material. Choosing the right slab, panel, or tile for a given project will depend on the project and the opinion of the consumer.

Working With Quartzite

When it comes to working with quartzite, the hardness (as we mentioned above) of the material plays a role in how it must be worked. For example, cutting a quartzite slab requires using a diamond blade for cutting hard stone like quartzite. Not all diamond blades are made to cut the same kinds of stone. Hard materials take certain blades to prevent chipping that might occur from the cutting process.

Other tools for quartzite are important too. For example, coring bits, polishing pads, and turbo blades are amond the equipment needed to work natural quartzite.

Working With Limestone

Just like hard quartzite requires specific tooling to fabricate, so too limestone is best fabricated and installed using tools that are designed for soft stone. Cutting soft stone can difficult using improper tools. Calcareous stone creates debris when it is cut just like all hard surfaces. The difference is that calcareous material is soft and can collect in the spaces that are part of the blade. This "gums" up the blade and inhibits the effectiveness with which the blade cuts. So blade producers make products for cutting softer stone. These products are, in some cases, labeled "marble blades" and are made in such a way that they do not gum up when being used to cut limestone and other calcareous material. Yes, there are benefits to using a blade designed for cutting calcareous stone like limestone.

Care & Maintenance of Limestone and Quartzite

As we have seen up to this point, quartzite and limestone have similarities and differences. And when it comes to caring for and maintaining these materials, the same holds true. Let's look at the similarities and differences in the care and maintenance of quartzite and limestone.

Similarities

Many similarities of natural stone are found in the fact that they are similar because they are natural stone. Let's look at some of these similarities.

Periodic Sealing

As we mentioned above, most natural stone is porous to one degree or another. Many hard surfaces are made from natural stone, including quartzite and limestone. This means that hard surfaces usually need to be sealed. Using a natural stone impregnating sealer slows the rate of absorption and allows for longer clean up times since oil and water based liquids remain on the surface longer. Both quartzite and limestone benefit from sealer applications.

Both quartzite and limestone are natural materials. Additionally, each of these is porous to a degree. Thus, sealing each of these materials is beneficial. But how often should this be done?

Regardless of which porous material you are sealing, you can use the same test to determine if it is needed. The test you will need to perform is a "water test" or "absorption test". This test is simple and easy to do. Just pour some water on the surface of the stone and observe how quickly the stone absorbs the water. A freshly sealed stone will not absorb the water as quickly. So if the water beeds up on the surface and stays there for a few minutes, the stone is not "thirsty", so-to-speak and does not need to be sealed.

Daily Cleaning

Daily cleaning is a must no matter which material you have. And when it comes to natural stone like quartzite and limestone, the type of cleaner you choose is important. Any stone surface that requires sealer is also going to need to be cleaned using cleaner formulated for the task. The wrong kind of daily cleaner destroys the sealer that is on the stone. Putting the sealer on periodically is of no use unless the proper sealer for natural stone is selected. Additionally, fortified stone polish is another product that consumers use for both quartzite countertops and limestone surfaces other than flooring or other surfaces than should not be slippery. Because of this, cleaning and polishing kits for stone are available.

Differences

As we have mentioned already, there are a number of similarities between quartzite and limestone. But there are also differences in how these materials are cared for and maintained. For example, limestone is a calcareous material whereas quartzite is not. Calcareous stone is susceptible to etching. An etch is a discoloration in the material. When acid reacts with calcareous stone, the calcite is dissolved, when this happens it changes the appearance of the material. Some surfaces are dull, others appear to be darker in the area where the acid was. That means consumers of limestone surfaces benefit from having an etch repair product on hand. Keep in mind that sealer does not protect calcareous surfaces from etching.

As we have seen, there are a number of similarities between natural quartzite and natural limestone. However there are differences as well. Each material is sufficient for multiple applications. Knowing a bit about these materials goes a long way toward selecting the right surface.