metamorphic

Quartzite

Metamorphic Quartzite (SiO2)

AI-generated identification · may be incorrect

Mohs hardness of 7, vitreous luster, granular crystal structure, conchoidal fracture, and colors ranging from white to gray, pink, or green.

Identified October 17, 2026More metamorphic →

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Physical properties

Mohs hardness of 7, vitreous luster, granular crystal structure, conchoidal fracture, and colors ranging from white to gray, pink, or green.

Formation & geological history

Formed through the metamorphism of quartz-rich sandstone under intense heat and tectonic pressure, commonly occurring in mountain-building belts.

Uses & applications

Used extensively in construction as crushed stone, railroad ballast, and decorative facing stone, as well as in manufacturing refractories.

Geological facts

Quartzite is extremely durable and weather-resistant, often forming prominent ridges and mountain peaks because it erodes much slower than surrounding rocks.

Field identification & locations

Identified easily by its inability to be scratched by a steel knife and its lack of effervescence with acid; found worldwide in ancient orogenic zones.