Description
Quartzite is a non-foliated metamorphic rock composed almost entirely of quartz. It forms when a quartz-rich sandstone is altered by the heat, pressure, and chemical activity of metamorphism. These conditions recrystallise the sand grains and the silica cement that binds them together. The result is a network of interlocking quartz grains of incredible strength. Most quartzite forms during mountain-building events at convergent plate boundaries. There, sandstone is metamorphosed into quartzite while deeply buried. Compressional forces at the plate boundary fold and fault the rocks and thicken the crust into a mountain range. Quartzite is an important rock type in folded mountain ranges throughout the world.
Uses
In architecture, marble and granite have been the favourite materials for thousands of years however quartzite, with a Mohs hardness of seven is superior to both in many uses. It stands up better to abrasion in stair treads, floor tiles, and countertops. It is more resistant to most chemicals and environmental conditions. It is available in a range of neutral colours that many people prefer. The use of quartzite in these uses is growing slowly as more people learn about it.
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