sedimentary

Rounded gray river pebble

Likely quartz-rich metamorphic or igneous pebble; exact identification requires testing

AI-generated identification · may be incorrect

Smooth, water-worn, medium-gray, fine-grained, and weakly lustrous with no visible crystals or cleavage. Likely hardness about 6–7 Mohs if quartz-rich; specific gravity approximately 2.6–2.8.

Identified September 6, 2026More sedimentary →

Explore Rounded gray river pebble in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Smooth, water-worn, medium-gray, fine-grained, and weakly lustrous with no visible crystals or cleavage. Likely hardness about 6–7 Mohs if quartz-rich; specific gravity approximately 2.6–2.8.

Formation & geological history

Natural abrasion in a stream, river, or beach rounded this specimen from a larger rock; its original geological age cannot be determined visually. The source may be granite, quartzite, basalt, or another durable gray rock.

Uses & applications

Suitable as a decorative pebble, paperweight, landscaping stone, or craft material; no reliable gemstone value is apparent.

Geological facts

The strongly rounded shape indicates prolonged transport or wave action. A streak, magnet, acid, hardness, and close-grained inspection would be needed for a more precise identification.

Field identification & locations

Check whether it scratches glass, leaves a white streak, attracts a magnet, or fizzes with dilute hydrochloric acid; these tests help distinguish quartzite, basalt, limestone, and iron-rich rocks. Commonly found in riverbeds, beaches, and gravel deposits.