sedimentary
River Pebble (Limestone / Siltstone)
Sedimentary pebble (predominantly CaCO3 or fine silicates)
AI-generated identification · may be incorrectHardness 3–6 Mohs, smooth rounded disc shape, pale grey to buff color, dull/matte luster, fine-grained clastic or microcrystalline texture.
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Physical properties
Hardness 3–6 Mohs, smooth rounded disc shape, pale grey to buff color, dull/matte luster, fine-grained clastic or microcrystalline texture.
Formation & geological history
Formed through mechanical weathering and fluvial abrasion of regional sedimentary or volcanic bedrock, smoothed by river or alluvial action.
Uses & applications
Commonly used as construction aggregate, decorative landscaping ground cover, or garden mulching.
Geological facts
Naturally rounded river pebbles owe their flattened or ellipsoidal shapes to repeated rolling and dragging against stream beds over thousands of years.
Field identification & locations
Identified by its well-rounded, water-worn edges, fine texture, and common presence in alluvial deposits and urban gravel near Armenia's Ararat basin.
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