metamorphic

Quartz-rich rock (possibly quartzite)

Quartzite, composed mainly of quartz (SiO₂)

AI-generated identification · may be incorrect

Small, rough tan-brown specimen with a granular, somewhat glassy appearance. Quartz has Mohs hardness 7, vitreous luster, and trigonal crystal structure; the photo does not show diagnostic cleavage or enough detail to confirm quartzite.

Identified September 30, 2026More metamorphic →

Explore Quartz-rich rock (possibly 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

Quartzite forms when quartz sandstone is recrystallized by heat and pressure during metamorphism; its age depends on the source rock and metamorphic event. The specimen’s exact origin cannot be determined from the image.

Uses & applications

Quartzite is used as building stone, aggregate, and sometimes decorative stone; this small unpolished piece is mainly suitable for collecting.

Geological facts

Quartzite is typically very hard and resists scratching by a steel knife, though impurities can alter its color and appearance.

Field identification & locations

Look for interlocking quartz grains and a surface that breaks through grains rather than around them; common in metamorphic mountain belts worldwide. The image is insufficient to distinguish quartzite from other quartz-rich rocks with certainty.