sedimentary

Pebble Gravel Mix (Quartzite, Basalt, Chert)

Alluvial River Gravel / Aggregate Clasts

AI-generated identification · may be incorrect

Hardness: 6-7 on Mohs scale. Colors: grey, tan, brown, black, white quartz. Luster: dull to vitreous when wet. Texture: sub-rounded to rounded water-worn pebbles.

Hardness: 6-7 on Mohs scale
Luster: dull to vitreous when wet

Identified July 24, 2026More sedimentary →

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Physical properties

Hardness: 6-7 on Mohs scale. Colors: grey, tan, brown, black, white quartz. Luster: dull to vitreous when wet. Texture: sub-rounded to rounded water-worn pebbles.

Formation & geological history

Formed through mechanical weathering and erosion of pre-existing igneous, metamorphic, and sedimentary rocks, transported and rounded by water in rivers or streams.

Uses & applications

Construction aggregate, concrete mix, decorative landscaping, driveway surfacing, and pathway material.

Geological facts

River gravel collections often contain dozens of different rock types in a single handfull, representing a wide geological cross-section of the upstream region.

Field identification & locations

Look for rounded, smooth edges indicating water transport. Commonly found along riverbeds, beaches, and in construction aggregate piles. Very low monetary value as individual pebbles.