sedimentary
River Stone (River Pebble)
River Stone (Composition: primarily Quartzite, Chalcedony, and silicate minerals)
Hardness: 6-7 on Mohs scale; Color: Gray, tan, or brown; Luster: Dull/matte when dry, waxy when wet; Crystal structure: Microcrystalline; Cleavage: None/Conchoidal.
- Hardness
- 6-7 on Mohs scale
- Color
- Gray, tan, or brown
- Luster
- Dull/matte when dry, waxy when wet
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Physical properties
Hardness: 6-7 on Mohs scale; Color: Gray, tan, or brown; Luster: Dull/matte when dry, waxy when wet; Crystal structure: Microcrystalline; Cleavage: None/Conchoidal.
Formation & geological history
Formed through thousands of years of water erosion in riverbeds and stream basins. Originally igneous or metamorphic rocks that were broken and rounded by hydraulic action.
Uses & applications
Landscaping, decorative garden paths, construction aggregate, aquarium substrate, and massage stones.
Geological facts
The smooth, rounded shape of river stones is a result of fluvial erosion, where rocks strike each other in moving water, a process called saltation.
Field identification & locations
Identified by its smooth, ellipsoidal shape and lack of sharp edges. Very common in old river channels and glacial deposits. Common globally.
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