metamorphic

Weathered quartz-rich rock, likely iron-stained quartzite

Quartzite (predominantly SiO₂); identification is provisional from the image

AI-generated identification · may be incorrect

Tan to rusty brown with a pale gray-green patch and dull, rough surface; quartz has Mohs hardness 7 and a trigonal crystal structure, but grain size and cleavage cannot be determined visually here.

Identified September 29, 2026More metamorphic →

Explore Weathered quartz-rich rock, likely iron-stained quartzite in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Tan to rusty brown with a pale gray-green patch and dull, rough surface; quartz has Mohs hardness 7 and a trigonal crystal structure, but grain size and cleavage cannot be determined visually here.

Formation & geological history

Quartzite forms when quartz-rich sandstone is recrystallized by heat and pressure during metamorphism. Its age and exact formation environment cannot be determined from the photograph.

Uses & applications

Quartzite is used as building and landscaping stone, aggregate, and sometimes decorative stone; this small, weathered specimen has little commercial value.

Geological facts

Iron-oxide staining commonly produces rusty colors in quartz-rich rocks. The pictured specimen is too weathered and small to establish a definitive rock identification.

Field identification & locations

Look for interlocking quartz grains and a hard surface that resists scratching by a steel knife; quartzite commonly occurs in metamorphic mountain belts worldwide. A close-up of a fresh broken surface would help confirm it.