metamorphic

Red Quartzite

Metamorphic Quartzite (SiO2)

AI-generated identification · may be incorrect

Hardness of 7 on the Mohs scale, reddish-brown color due to iron oxide impurities, vitreous to greasy luster, massive crystal structure with interlocking quartz grains, conchoidal fracture, specific gravity around 2.65.

Identified July 30, 2026More metamorphic →

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Physical properties

Formation & geological history

Formed from quartz-rich sandstone subjected to high heat and pressure during regional metamorphism, typically dating from the Precambrian to Paleozoic eras.

Uses & applications

Used in construction, as a decorative stone, crushed stone for road bases, and sometimes in landscaping and interior countertops.

Geological facts

Quartzite is extremely durable and weather-resistant, which is why mountain ridges formed of quartzite often persist as prominent crests.

Field identification & locations

Identified by its inability to be scratched by a steel knife, granular quartz texture on fractured surfaces, and lack of fizz when tested with hydrochloric acid. Found globally in ancient mountain belts.