sedimentary

Weathered quartz-rich rock, likely sandstone or quartzite

Quartz arenite (sandstone) or quartzite; predominantly SiO₂

AI-generated identification · may be incorrect

Tan-brown, opaque, dull to slightly vitreous surface with apparent granular texture and iron-oxide staining. Quartz has Mohs hardness 7; sandstone is commonly porous and friable, while quartzite is harder, denser, and strongly indurated; cleavage is absent.

Identified August 12, 2026More sedimentary →

Explore Weathered quartz-rich rock, likely sandstone or quartzite in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

If sandstone, it formed from cemented quartz sand in a sedimentary environment, commonly during the Paleozoic–Cenozoic; if quartzite, later metamorphism recrystallized the sandstone. The image alone cannot establish a precise age or subtype.

Uses & applications

Common sandstone is used for construction, paving, aggregate, and decorative stone; quartzite is used as aggregate, slabs, and ornamental material. This small weathered specimen has little commercial value.

Geological facts

The brown coloration likely comes from oxidized iron minerals such as hematite or goethite. A glass-scratch test and inspection of fresh break surfaces can distinguish quartzite from softer sandstone.

Field identification & locations

Common worldwide, especially in former beaches, deserts, river deposits, and metamorphic belts. Test whether it scratches glass and whether grains crumble under a steel point; acid reaction would suggest carbonate cement, not pure quartz arenite.