metamorphic

Quartz-rich metamorphic rock, likely quartzite

Quartzite (predominantly quartz, SiO₂); identification is tentative from the image

AI-generated identification · may be incorrect

Gray to tan, coarse and sparkly with interlocking grains; quartz has Mohs hardness 7, vitreous luster, and no cleavage. The image does not show enough detail to confirm texture or composition.

Identified September 26, 2026More metamorphic →

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Physical properties

Gray to tan, coarse and sparkly with interlocking grains; quartz has Mohs hardness 7, vitreous luster, and no cleavage. The image does not show enough detail to confirm texture or composition.

Formation & geological history

Forms when quartz-rich sandstone is recrystallized during metamorphism; its age depends on the source rock and metamorphic event and cannot be determined visually.

Uses & applications

Quartzite is used as crushed stone, building and decorative stone, and sometimes as a lapidary material.

Geological facts

True quartzite is highly resistant to scratching and weathering; some rocks sold as quartzite are actually quartz-rich sandstone.

Field identification & locations

Look for interlocking quartz grains and a hard surface that scratches glass; a hand specimen or hardness test would help distinguish it from sandstone or another quartz-rich rock. Quartzite occurs in metamorphic belts worldwide.