metamorphic

Quartzite

Metamorphic Quartzite (SiO2)

AI-generated identification · may be incorrect

Hardness of 7 on the Mohs scale; Color typically white, gray, or shades of pink, yellow, and orange due to iron oxide impurities; Luster is vitreous to greasy; Crystal structure is trigonal (microcrystalline or interlocking quartz crystals); Cleavage is none (fractures conchoidally); Specific gravity is 2.65.

Identified August 3, 2026More metamorphic →

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Physical properties

Formation & geological history

Formed through the metamorphism of quartz sandstone or chert under high temperature and tectonic pressure, typically during mountain-building events over millions of years.

Uses & applications

Used in construction, as crushed stone for roadbeds, railway ballast, dimension stone, roofing granules, and occasionally in decorative applications or lapidary work.

Geological facts

Quartzite is extremely durable and resistant to chemical weathering, which is why ridges formed of quartzite often persist as prominent hills or mountain ranges.

Field identification & locations

Can be identified by its inability to be scratched by a steel knife (hardness > 5.5), its conchoidal fracture, and the fused, interlocking sugary texture visible on broken surfaces. Found worldwide.