metamorphic

Weathered quartz-rich rock (likely quartzite)

Quartzite, composed predominantly of quartz (SiO₂); identification is tentative from the photo

AI-generated identification · may be incorrect

Pale tan to gray, rough and dull, with a granular, uneven surface and no obvious cleavage. Quartz has Mohs hardness 7; the specimen’s hardness and specific gravity cannot be confirmed visually.

Identified September 28, 2026More metamorphic →

Explore Weathered quartz-rich rock (likely quartzite) in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Pale tan to gray, rough and dull, with a granular, uneven surface and no obvious cleavage. Quartz has Mohs hardness 7; the specimen’s hardness and specific gravity cannot be confirmed visually.

Formation & geological history

Quartzite forms when quartz sandstone is recrystallized by heat and pressure, commonly during regional metamorphism. Its age depends on the source sandstone and metamorphic event; neither can be determined from the image.

Uses & applications

Quartzite is used as crushed aggregate, road stone, building stone, and sometimes decorative material. This small, unpolished piece has little commercial value.

Geological facts

Quartz-rich rocks can look pale and granular, but several rocks—including weathered sandstone—can appear similar in a photograph.

Field identification & locations

The reported southeast Alaska location is geologically plausible for quartz-bearing metamorphic rocks. Check for interlocking quartz grains and whether a steel nail fails to scratch it; a grainy or easily scratched specimen could instead be sandstone or another local rock.