Lustro Italiano > Stone Reference > Quartzite

Natural Quartzite


Description:Natural quartzite is a rock that forms through a natural process. Here is some information regarding natural quartzite.

Formation Process: Natural quartzite is a metamorphic rock made up almost entirely of quartz. Quartzite forms when sandstone is heated and squeezed by natural rock-forming processes. During this process the grains of sand fuse together forming a different type of rock called quartzite.

Appearance: Quartzite forms in various colors but is usually light colored and can contain streaks of color formed by various other minerals in the rock.

Composition: Natural quartzite is made up almost entirely of quartz and can also contain other minerals such as iron oxide, mica, kyanite, and other minerals.

Composition of Natural Quartzite

Quartzite is a natural stone that is composed mainly of the mineral quartz. It can contain other minerals (such as iron oxide or mica) as well but it is made up of mostly quartz. Here are some of the components than can be in quartzite:

  • SiCO2 (Silica)
  • AB2–3(x, Si)4O10(0, F, OH)2 (Mica)
  • Fe2O3 (Iron Oxide)
  • Al2SiO5 (Kyanite)

Natural Quartzite Characteristics

Depending on the amount of and type of impurities in a given quartzite slab, it can range from white to various shades of grey or tan in most cases. However, Quartzite can occur in various colors. The porosity of a particular stone can vary depending on the composition. Additionally, quartzite normally has a hardness of about 7 on the Mohs scale of mineral hardness.

Applications and Uses

Quartzite is used for many applications and for a variety of purposes. For example, quartzite is a material that is used for:

  • Stairs
  • Flooring
  • Worktops
  • Countertops
  • Vanity Tops
  • Roofing Tiles
  • Railway Ballast (Crushed)
  • Road Construction Material (Crushed)

Advantages of Natural Quartzite

One advantage to quartzite is that it has a unique, elegant look and adds value to a structure in which it is used. It is a very hard material and is not easily scratched or chipped. This means it is a durable natural stone.

Since it is a natural material, quartzite is compatible with a number of other materials. The colors of quartzite also make it complimentary to many other materials. Quartzites are available in white, tans, greys, and many other neutral colors. Yet, there are non-neutral quartzite colors as well.

Quartzite's Disadvantages

One drawback to using quartzite is that it is porous. This is the case for all natural stone materials. Each natural stone is porous to a one degee or another. This means it has the potential for being susceptible to staining via liquid substances. Yet, there are ways to care for and maintain quartzite.

Additionally, when fabricating quartzite it is necessary to use a diamond blade that is made for cutting extremely hard materials. Hence, finding tooling designed for effectively cutting very hard materials is a key to successfully working with quartzite stone.

Care and Maintenance

Caring for natural quartzite is simple. However, simple does not necessarily mean it is easy. One of the simplest ways to care for quartzite is to regularly seal it. Sealing natural stone can help protect it from staining that could occur from colored liquid that could get into the pores of the stone and discolor it. Here are some practical steps that can be taken to care for and maintain natural quartzite.

  1. Make sure to initially seal quartzite countertop surfaces to help them resist oil and water based stains.
  2. Use a pH neutral cleaner on your quartzite surfaces. Acidic cleaners breakdown the sealer and allow stain causing liquids to penetrate the pores of the stone.
  3. Periodically use an impregnating sealer to renew the seal that was added right after installation.

In addition to the care tips above, you can use a fortified natural stone polish on the surface of natural quartzite countertops (not flooring) to build up the seal a little at a time. By using the pH neutral stone cleaner and natural stone polish, you can consistently maintain the appearance of your quartzite countertop surfaces.

With quartzite there is no need to have an etch remover on hand to care for etching. Etching occurs when acid dissolves calcite that is present in various natural stone materials. Calcareous stones such as natural marble, natural limestone, and natural travertine are composed primarily of calcium carbonate in the form of calcite. However, quality true quartzite contains no calcite and therefore should not etch. Some have heard that certain quartzite stones do contain calcite. However, geologist Karin Kirk wrote an article in 2017 entitled The Definitive Guide to Quartzite In that article, Karin made the following statement regarding quartzite:

I’ll get right to the point: quartzite is commonly mislabeled. Some quartzite is the real deal, but sometimes marble or dolomitic marble are labeled as quartzite. Because each of these stones behaves differently, people might understandably conclude that quartzite is variable. But it isn’t; quartzite has very consistent properties. Unfortunately it has variable labeling.

So even though quartzite may in some ways resemble marble in appearance, it is a very different material. A stone that is labeled "quartzite" should not etch becasue it does not consist of calcium carbonate (calcite). It will however, benefit from regular sealing since like all other natural stone, it will have a degree of porosity.

As we have seen, quartzite is a very practical natural stone that can be used for a number of applications. It offers advantages over other materials but like everything else, it is not the perfect material for every situation or application. The beauty and cost effectiveness of quartzite though, may make it a good choice for a number of projects.