metamorphic

Possible iron-stained quartzite or sandstone fragment

Quartzite (mostly SiO₂), possibly ferruginous sandstone

AI-generated identification · may be incorrect

Brown-red, rough and granular with white quartz-rich patches and earthy/dull luster; quartz hardness is about Mohs 7, with no obvious cleavage. The image is insufficient to distinguish quartzite confidently from iron-stained sandstone.

Identified September 6, 2026More metamorphic →

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Physical properties

Formation & geological history

Quartzite forms when quartz-rich sandstone is recrystallized during metamorphism, typically during regional mountain-building; sandstone forms by sediment burial and cementation. No precise geological age can be assigned from the photograph.

Uses & applications

Quartzite is used as aggregate, road stone, landscaping material, and occasionally as a decorative stone; attractive pieces may be collected, but this specimen appears ordinary.

Geological facts

The reddish-brown coloration commonly comes from iron oxides such as hematite or goethite coating or cementing the quartz grains.

Field identification & locations

Look for gritty quartz grains, strong resistance to scratching, and lack of fizz with dilute hydrochloric acid; a steel nail should not scratch quartzite. Common worldwide in metamorphic belts and quartz-rich sedimentary formations.