sedimentary (alluvial deposit)

River Rock (Quartz-dominated)

Silicon Dioxide (SiO2) mixture with varied clastic sediments

AI-generated identification · may be incorrect

Hardness: 7 (Mohs scale), Color: tan, white, brown, and grey. Luster: dull to waxy (smooth/polished appearance). Structure: amorphous to microcrystalline. Cleavage: none/conchoidal fracture.

Hardness: 7 (Mohs scale), Color: tan, white, brown, and grey
Color: tan, white, brown, and grey
Luster: dull to waxy (smooth/polished appearance)

Identified March 24, 2026More sedimentary (alluvial deposit) →

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Physical properties

Hardness: 7 (Mohs scale), Color: tan, white, brown, and grey. Luster: dull to waxy (smooth/polished appearance). Structure: amorphous to microcrystalline. Cleavage: none/conchoidal fracture.

Formation & geological history

Formed through the erosion of larger rock formations over millions of years; these specimens are shaped by hydraulic action in riverbeds and glacial runoff during the Holocene and Pleistocene epochs.

Uses & applications

Used primarily in decorative landscaping, interior design (fountains/planters), construction aggregate, and aquatic environments due to pH neutrality.

Geological facts

River rocks are naturally tumbled 'clastic' sediments. The smoothness of these stones is a direct indicator of the distance they have traveled from their original mountain source—the smoother the stone, the longer the journey.

Field identification & locations

Identify in the field by their rounded, water-worn edges and smooth texture. Commonly found in floodplains, deltas, and dry riverbeds. For collectors, look for unique patterns like 'banded' chert or pure translucent quartz among the mix.