sedimentary
River Pebbles (Quartzite / Granite Pebbles)
SiO2 (Quartz-rich detrital gravel)
Hardness 6-7 on Mohs scale; color ranges from light grey, cream, and speckled brownish-grey; dull to sub-vitreous luster; smooth, water-worn rounded texture with granular crystalline structure.
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Physical properties
Hardness 6-7 on Mohs scale; color ranges from light grey, cream, and speckled brownish-grey; dull to sub-vitreous luster; smooth, water-worn rounded texture with granular crystalline structure.
Formation & geological history
Formed by natural weathering, erosion, and transport by moving water in rivers, streams, or lake shores over hundreds to thousands of years, smoothing down larger rock fragments.
Uses & applications
Used primarily for landscaping, decorative stone displays, aquariums, drainage, and as natural pocket stones or stress relievers.
Geological facts
River pebbles undergo natural tumbling through high-energy water currents, which wears away softer minerals and sharp edges, leaving behind mostly durable quartz-rich and feldspathic rocks.
Field identification & locations
Identified by their smooth, rounded edges and water-worn surfaces without sharp fractures. Commonly found along stream beds, river banks, alluvial plains, and beaches.
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