Natural Stone Types and Their Properties: An Overview
When selecting the perfect natural stone type for your project, it is important to consider the properties, durability and chemical makeup of all natural stones. Researching endless stone families and pondering the possibilities of how each material will react to your day-to-day activities is a chore! That’s why the Aria team has prepared the perfect cheat-sheet of all stone types, to make your search just a little easier.
Properties of Granite
Categorized as an igneous stone and formed from the slow crystallization of liquid magma below the Earth’s surface, granite was once molten lava!
Granite is one of the hardest and most durable natural stone types, requiring little to no maintenance. Scoring about a 6 on the Mohs Hardness Scale, granite is the perfect candidate for outdoor applications, flooring, and countertops that take a lot of beating from everyday use. It is virtually impossible to scratch, stain or etch this stone, so look no further if you are searching for a material that will outlast messy kids and cooking disasters!
Properties of Quartzite
The long and tedious process of sand compression and heating leads to create the incredibly dense and durable quartzite. The Mohs Hardness Scale classifies quartzite at a 7, higher than its neighbor granite, which on the same scale measures between 6-6.5. To further illustrate, a kitchen knife and glass measures a 5 on the Mohs Hardness Scale. Therefore, scratches should not be an issue when using quartzite in your home, even in high traffic areas and highly used spaces, such as the kitchen. Staining and etching will not be a problem either, since quartzite is relatively non-porous.
People are to the unique and vibrant hues found in quartzite, so if you are looking for a statement pop of color in your home, quartzite is the material to explore!
Properties of Marble
Marble is a metamorphic stone that forms when limestone undergoes the heat and pressure of metamorphism. Composed primarily of the mineral calcite, and usually contains other minerals, such as clay, quartz, pyrite, and graphite.
Marble is a naturally softer stone (scoring about a 4 on the Mohs Hardness Scale) when compared to granite or quartzite. So it is more susceptible to staining, scratching and acid etching through daily use. However, there are many simple precautions you can take that will keep marble looking like new for years to come! Luckily, stone can be restored repeatedly without concern, and maintenance definitely does not have to be stressful or difficult. Read more about marble and how to maintain it here.
Properties of Onyx
Onyx is a unique natural stone that originates from dripstone deposits of limestone caves. When water drips from stalactites and stalagmites within these caves and evaporates a compound called calcium carbonate is left behind. This causes the stone’s colorful veins, swirls, and patterns unique to onyx.
Onyx is relatively soft, ranking softer than marble on the Mohs Hardness Scale, and therefore has the potential to etch and stain. However, a sealer prevents wear and tear over time. Feature walls, countertops, art pieces and fireplaces are all especially great examples of ways to incorporate onyx into your home. Most onyx applications can be backlit to enhance the stone’s natural translucency.
Properties of Schist
Schist is a metamorphic rock, formed from the metamorphosis of mudstone or shale. When mudstone is subjected to extreme temperatures and pressure within the Earth, it becomes what we call “slate”. Sometimes, this “slate” undergoes even further metamorphosis before surfacing and hardening, therefore creating schist. In short, slate is the first step in the creation of schist, much like a caterpillar is the first step in the life cycle of a butterfly!
Schist ranks the same level of hardness as marble on the Mohs Hardness Scale, a 4. It is grainy in texture, quite porous, and can shed sparkles or flakes over time, similar to how slate reacts to the touch. If used for applications other than feature walls or fireplaces, Schist should be sealed and maintained regularly to protect its delicate surface. Although this stone is somewhat fragile, it makes for a beautiful project because of its unique appearance and texture.
Properties of Calcite
Calcite is a transparent or translucent natural stone found in both crystalline and massive forms, such as a stone slab. Although crystals of calcite are usually translucent or colorless, they can at times exhibit a wide variety of hues depending on the crystal’s chemical makeup. Calcites can have soft veins of light blue, green and other light colors, in addition to clear, sparkling crystals throughout the material.
Calcite is a softer stone – more comparable to marble in terms of hardness, ranking about a 3 on the Mohs Hardness Scale. They can scratch, etch and stain just like marble can if not sealed or cared for properly. However, with proper care and a skilled fabricator, this stone makes a beautiful fit for any application!
Properties of Travertine
Travertine is very similar to onyx in nature and in terms of durability. Travertine, at times, can even contain mixtures of translucent onyx within itself – making it a great candidate for backlighting! Much like onyx, it’s formed from limestone drip deposits from caves and hot springs, or from the evaporation of river water. Therefore, it’s classified as a sedimentary rock.
This stone is relatively soft and porous, so it would be wise to seal and protect it from acid and debris penetrating into the material. Known for having naturally occurring small holes throughout the material, Travertine can remain a textured surface or filled. If you use Travertine for a countertop application, always use a neutral detergent to clean it.
However, interestingly enough, the primary use of travertine is actually for construction! Temples and monuments all over the world used travertine, but you can use it as paving patios, courtyards, and paths. Travertine’s colors are commonly warm, and are white, beige, gold, brown, and even red!
Properties of Soapstone
Soapstone is a tricky material to categorize. It technically ranks the lowest on the Mohs Hardness Scale (#1, to be exact) but don’t let the number fool you. Soapstone is composed mostly of the mineral “talc”, which is the softest mineral in the world. However, although talc is soft, it is also super dense, which actually makes soapstone very durable! Okay, so here’s a breakdown of the confusing part:
Soapstone DOES NOT stain or etch. Why? It is a non-porous stone. Therefore, you don’t ever need to seal it. It would be pointless to seal soapstone since it has virtually no pores for debris to sink into! It is impervious to most kitchen chemicals, acids and liquids, in fact.
Soapstone DOES scratch. Why? Because soapstone is mostly of that “talc” stuff, a very soft mineral.
How do you repair scratches then? Look no further than your garage for some sandpaper! Deep scratches can be smoothed down with 120-grit sandpaper, then finished by apply a coating of mineral oil to clean it up. Mineral oil is what you should use instead of a typical “sealer” to keep your soapstone looking vibrant and clean.
Soapstone IS HEAT RESISTANT. That’s why chefs love it! You could *gently* set a boiling hot pan on a soapstone countertop and it wouldn’t burn. It is almost completely heat-proof due to the incredible density of the material. Bon appétit!