metamorphic

Quartzite

Quartzite, composed predominantly of quartz (SiO₂)

AI-generated identification · may be incorrect

The specimen appears pale tan-gray, granular, and nonmetallic, with a sugary, crystalline texture. Quartz has Mohs hardness 7, a trigonal crystal structure, no cleavage, and specific gravity about 2.65; a photo cannot confirm the rock identification or properties.

Identified October 13, 2026More metamorphic →

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Physical properties

Formation & geological history

Quartzite forms when quartz-rich sandstone is recrystallized under heat and pressure, commonly during regional metamorphism. Its age depends on the original sandstone and metamorphic event.

Uses & applications

Used as building and decorative stone, aggregate, and landscaping material; attractive pieces may be collected or polished.

Geological facts

Unlike many rocks, quartzite can fracture through quartz grains rather than around them, making it notably durable and resistant to weathering.

Field identification & locations

Look for a hard, quartz-rich rock with interlocking grains; it should resist scratching by a steel knife and may scratch glass. It occurs in metamorphic mountain belts worldwide; the image alone is insufficient to distinguish it confidently from other quartz-rich rocks.