metamorphic

Quartz-rich river pebble, possibly weathered quartzite

Quartzite; predominantly crystalline SiO₂, though exact identification is uncertain from the photograph

AI-generated identification · may be incorrect

Tan, brown, and rusty surfaces with translucent gray-white quartz, uneven granular fracture, and little visible cleavage; quartz hardness is 7 Mohs, vitreous luster, specific gravity about 2.65. The specimen appears water-worn and iron-stained.

Identified September 3, 2026More metamorphic →

Explore Quartz-rich river pebble, possibly weathered 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

Likely a durable siliceous clast eroded from older metamorphic or sedimentary rocks and transported by the Glan River. Quartzite forms when quartz-rich sandstone recrystallizes during metamorphism; the source rock may be Paleozoic or older, but the specimen’s age cannot be determined visually.

Uses & applications

Common quartzite is used as aggregate, road stone, paving, and decorative stone; attractive pieces are collected but usually have modest value.

Geological facts

The rusty colors generally reflect iron oxides coating or staining the quartz. A steel file should not scratch fresh quartz surfaces, whereas ordinary glass can be scratched.

Field identification & locations

Quartz-rich river cobbles are plausible in the Pfalz and may also be vein quartz or strongly silicified sandstone; a fresh broken surface and a hardness test would distinguish them. Likely value is $1–$10 as a loose common specimen, occasionally $10–$30 if unusually attractive.