sedimentary
River Pebbles and Cobbles
Mixed Siliciclastic Sediments (Quartzite, Chert, and Sandstone clasts)
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
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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.
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