If you have looked for stone for building projects, you realize there are so many different kinds of stone and stone-like materials available. It can be overwhelming how many options there are. Quartz, marble, and quartzite are just a few that are popular today. Each is a unique material that will exceed your expectations when used in the correct way, but also let you down if used improperly. So which stone material should you use?
The first way to differentiate stone materials is by understanding the difference between natural stone and man-made, stone-like products. Natural stone has undergone geological processes and each piece is one-of-a-kind. Man-made stone products are created in a factory by mixing natural and sometimes unnatural products using extreme pressure and heat, and often digital printing, so many pieces can look the same.
Natural Stone is any rock found in nature. The three types of natural stone are sedimentary, magmatic, and metamorphic. They are formed by natural geological processes over thousands, millions or even hundreds of millions of years. Every piece of natural stone is a wholly unique blend of colors and minerals. Each type of stone will have its own specific of properties. The most common types of natural stone are quartzite (metamorphic), granite (magmatic), marble and limestone (sedimentary). But there are a few others that are often used in construction applications – soapstone, travertine (sedimentary) and onyx.
Marble & Limestone
Marble and limestone are sedimentary stone. Sedimentary stones were formed in places where layers of sediments were deposited, such as the bottoms of lakes, rivers and oceans. They started at the surface and were pushed down. These successive layers are what give many marbles their gorgeous wavy veins. Marble and limestone are “Calcareous” stones, which means, these materials are mainly composed of calcium carbonate rocks. These rocks are sensitive to the mild acids typically found in your kitchen, so they are often recommended for other indoor areas like bathrooms or fireplace surrounds and mantels. What is the difference between marble and limestone? Marble simply has been under more heat and pressure for a longer period of time than limestone, which is why it can be polished to a high shine, whereas limestone will have a patina finish.
Travertine is another example of a calcareous stone. It is a kind of limestone that forms from a chemically unique sedimentary stone, creating many small holes in the body of the stone, allowing larger crystalline structures to grow. These holes are often filled in the processing of the slabs with cement or epoxy, giving travertine its unique look. Travertine, like marble and other limestones, is best used for indoor applications, away from the thermal shock caused by abrupt and large changes in temperature.
While sedimentary stones started at the surface and were pushed down, magmatic stone forms deep within the earth and is pushed up towards the surface. “Magmatic” stone is formed by volcanic activity or melting. Granites are an example of magmatic stone. These stones were formed when liquid magma cooled and became very hard. All granites are also ”Siliceous” stone, which means they are composed from silicates like feldspar, mica and quartz. Some granites have veins through their composition which are the result of unique metallic crystals that were deposited along with the mineral crystals in the magma. Other granites were formed when different magmas blended together before they hardened. The exact mix and orientation of these crystals, plus the mineral and chemical reactions that took place over millions of years formed all those unique kinds of granite that we see today. As a result of these processes granite is very hard, resistant to most house hold chemicals and often freeze/thaw stable.
Sometimes, while forming in the ground, sedimentary and magmatic stones can be changed by additional heat or pressures. These changed stone are called “Metamorphic” stones. Some granites are metamorphic as well as magmatic, which is one of the reasons that there’s such a wide diversity of granites.
Quartzite is a metamorphic stone. Quartzite is sandstone that has been put under tremendous tectonic pressure transforming it into quartz crystals and then cementing them together. While often composed mostly of the same siliceous stone like granite, quartzite can also include a blend of the calcareous stone like limestone and marble. Visually quartzite can have veining similar to many marbles or a beautiful almost transparent crystalline structure. As a result, not all quartzite is as acid-resistant as granite and this should be considered when deciding upon its application in your home.
Soapstone is another example of a metamorphic rock. Soapstone is mainly composed of talc and magnesium that have been placed under great heat and pressure resulting it a dense but relatively soft stone. It’s this unique composition that gives this material a “soapy texture” and makes it resistant to the mild acids in your kitchen. However, unlike most stone products, soapstone is more easily scratched by kitchen utensils. Scratches have to be removed with a light sanding and re-sealing of the stone.
Onyx is an example of a metamorphic, calcareous stone. The type of onyx used in counter or furniture applications is not the same as the gemstone onyx. This onyx is a banded calcite and is softer than “true onyx”. It is translucent and available in small slabs often for back-lit applications. Since it is a calcareous stone it is not resistant to mild acids.
Most Man-Made Stone slabs can be divided into one of two types, Engineered Quartz slabs or Porcelain slabs. Both have been fabricated using specific and often closely guarded manufacturing processes that ensure they will perform according to their design criteria. Both processes work to mimic nature by highly compressing the material (like sedimentary stone), and heating the stone (like magmatic stone).
Engineered Quartz is a man-made material subjected to rigorous fabrication processes that results in a product with very specific properties. This material is often easy to spot due to its uniform and consistent look. Engineered Quartz products, sometimes just shortened to “quartz”, are a mix of quartz crystals and some silica, which are then blended with an epoxy resin, cast into a single block and cut into slabs. These quartz products are extremely hard, chemically-resistant, almost non-porous, and they are very consistent in their colourations. This process makes quartz products a very good choice for indoor applications like kitchens and bathrooms. You should know that Engineered Quartz products do not handle UV-light as well as Natural Stone products, so are they not recommended for exterior applications. Also because epoxy resins are used as the binder in the fabrication process these materials can be scorched if exposed to high heat.
Porcelain shares some of the benefits of quartz, but is often manufactured to mimic the look of natural stone. It is a vitrified pottery material that can be somewhat translucent like glass, or opaque with a custom pattern. Porcelain is made from heating a mix of powdered stone and clay at about 1450°C. The high temperature causes the stone to vitrify into a dense, highly durable material, while the clay helps it keep its shape. Impurities such as feldspars, mineral oxides, and silica exist in the clay, but they add to its strength and color.
Like Engineered Quartz, porcelain products are very strong and hard. Porcelain is almost as hard as quartz, and much stronger than granite. Porcelain is also extremely stain resistant and heat resistant, and virtually impervious to water (its absorption rate is less than 0.5%). Unlike quartz slabs, their thinness and light weight makes them uniquely suitable for creative applications such as backsplashes, shower walls and complete floor to ceiling wall applications like bathroom walls and fireplace surrounds. They can also be used for most counter and kitchen island applications. Unlike Engineered Quartz these Porcelain slabs are UV light-resistant, heat resistant and freeze/thaw stable so they can also be used outside. Because porcelain is a 100% natural product made of raw and clay-based materials, it can be recycled.
Porcelain does have its drawbacks. Because it is a glass-like product, it will crack under blunt force. It’s strong but not that strong. As long as you don’t take a meat cleaver or a hammer to it, it will be fine. Porcelain also has limited edge profile options, since it is a thinner material.
The latest manufacturing technology now allows for sintered stone, which is similar to the porcelain manufacturing process, but uses even more extreme pressure (25,000 lbs) and heatso that resins do not need to be used. The resulting product is stronger, more heat resistant, and available in thicknesses greater than porcelain.
When choosing between quartz, porcelain, and sintered stone, it is important to know they feel very different to the touch. Also the appearance of quartz (color and pattern) permeate the entire slab, whereas patterns on porcelain are only on the surface, causing a certain lack of depth. While not immediately noticeable, it can become obvious if the surface is becomes marred, such as with a ceramic knife. The nature of the countertop or surface may appear less “natural-stone like” because the veining or pattern does not extend below the surface. Sintered stone often does a better job at creating a stone-like texture.
Now that you know more about the different stone products, how each is unique, and what they’re best used for, you can start specific materials for your project. Contact us, as we are here to help.