sedimentary

River Pebbles and Cobbles

Mixed Siliciclastic Sediments (Quartzite, Chert, and Sandstone clasts)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs); Color: Tan, brown, gray, and cream; Luster: Dull to sub-vitreous; Texture: Rounded to sub-angular due to water erosion; Composition: Predominantly Silica (SiO2).

Hardness: 6-7 (Mohs)
Color: Tan, brown, gray, and cream
Luster: Dull to sub-vitreous

Identified July 14, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs); Color: Tan, brown, gray, and cream; Luster: Dull to sub-vitreous; Texture: Rounded to sub-angular due to water erosion; Composition: Predominantly Silica (SiO2).

Formation & geological history

Formed through the mechanical weathering of larger rock formations, transported by water over long distances which rounds the edges, and deposited in riverbeds or alluvial fans.

Uses & applications

Used in landscaping, construction (as aggregate), garden decoration, and drainage systems.

Geological facts

The smoothness of these rocks indicates they have spent a significant amount of time being tumbled by moving water. This specific mix appears to be common landscape gravel or naturally collected river stones.

Field identification & locations

Identify in the field by their rounded shape and presence in fluvial environments. They are ubiquitous in riverbeds, deltas, and glacial outwash plains.