When a quartz-rich sandstone is altered by the heat, pressure, and chemical activity, we get the quartzite, a metamorphic rock which is emerging as one of the most interesting varieties of natural stones for civil construction, architecture and decoration.
Abundant on Brazilian soil, this rock is becoming more known, thanks to a recent technological increase. With the machine’s evolution, cutting techniques became better, extraction became easier and the industrialization process became more modern and less expensive.
“Quartz is 7 on Mohs hardness scale. That means it’s harder than glass and harder than a knife blade. These things are easy to test with a sample of stone”, defines The Definitive Guide to Quartzite, published by the Natural Stone Institute, a trade association of the natural stone industry with more than 2,000 members in over 50 countries.
According to the guide, one does not need to be a geologist to appreciate the hardness and durability of quartzite, one of the most robust and chemically resistant rocks found at Earth’s surface.
Uses and composition
Quartzite has a lot of uses in construction, manufacturing, architecture and decorative arts. Its properties are superior to many currently used materials, but its consumption is still very shy.
In architecture, marble and granite have been the favorite materials for thousands of years. The use of quartzite is growing slowly as more people learn about it.
The color palette of pure quartzite usually goes from white to gray. Some pieces could be pink, red, purple or get tones of yellow, orange, brown, green and blue, depending on due to varying amounts of iron oxide or other minerals.
With greater toughness, quartzite stands up better to abrasion in stair treads, floor tiles, and countertops, for example. It is also more resistant to most chemicals and environmental conditions.
Concerning porosity, The Definitive Guide to Quartzite explains that quartzite has a range of porosities. Some have been highly metamorphosed, and the minerals are bonded together tightly. Others have been exposed to less intense pressure, so they are more porous.
Besides that, quartzite has a network of interlocking quartz grains with incredible strength. It forms an interlocking structure.
According to the guide from Natural Stone Institute, when the mountain ranges are worn down by weathering and erosion, less-resistant and less-durable rocks are destroyed, the quartzite remains.