sedimentary

Tumbled sandstone pebble

Quartz-rich sandstone, commonly arkose or ferruginous sandstone

AI-generated identification · may be incorrect

Typically Mohs 6–7, matte to dull earthy luster, orange-brown from iron-oxide staining, and composed mainly of rounded quartz grains cemented by silica, calcite, or iron oxides. The smooth rounded shape indicates natural abrasion or tumbling; cleavage is absent and specific gravity is about 2.2–2.7.

Identified August 26, 2026More sedimentary →

Explore Tumbled sandstone pebble 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

Sandstone formed when deposited sand was compacted and cemented, generally in river, desert, beach, or shallow-marine environments; its exact geological age cannot be determined from the photograph. The specimen was likely mechanically polished or naturally water-worn.

Uses & applications

Used mainly as a decorative or lapidary pebble, worry stone, craft material, or teaching specimen; sandstone is also widely used as building and paving stone.

Geological facts

The orange coloration commonly reflects hematite or limonite coatings on quartz grains. Grain texture and a faint sandy feel on an unpolished edge help distinguish it from homogeneous jasper or glass.

Field identification & locations

Common worldwide, especially in sedimentary basins; inspect a fresh edge with a hand lens for visible sand grains and test hardness against steel or glass. Exact identification requires a close-up, streak, and acid test.