metamorphic
Quartzite
Metamorphic Quartz Rock (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, vitreous luster, commonly white, gray, or reddish-brown due to iron impurities, with a massive or granular crystal structure.
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Physical properties
Hardness of 7 on the Mohs scale, vitreous luster, commonly white, gray, or reddish-brown due to iron impurities, with a massive or granular crystal structure.
Formation & geological history
Formed through the metamorphism of quartz-rich sandstone under intense heat and tectonic pressure, typically over hundreds of millions of years.
Uses & applications
Used extensively in construction, railroad ballast, decorative aggregates, and for manufacturing refractory bricks and ferrosilicon.
Geological facts
Quartzite is extremely durable and weather-resistant, which is why ridges formed of quartzite often persist as prominent mountain crests.
Field identification & locations
Identify in the field by its inability to be scratched by steel and its tendency to fracture across rather than around the quartz grains. Found globally in mountainous regions and ancient orogenic belts.
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