igneous
Rounded river pebble, likely quartz-rich sandstone or weathered igneous rock
Indeterminate; possibly quartzite, sandstone, or fine-grained granitic rock
AI-generated identification · may be incorrectSmall, naturally rounded gray-brown pebble with a dull to faintly earthy luster and no visible crystals or cleavage. Estimated hardness is about 5–7 Mohs, depending on composition; specific gravity likely 2.5–2.7.
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Physical properties
Small, naturally rounded gray-brown pebble with a dull to faintly earthy luster and no visible crystals or cleavage. Estimated hardness is about 5–7 Mohs, depending on composition; specific gravity likely 2.5–2.7.
Formation & geological history
Rounded by abrasion in a stream, beach, or gravel deposit; its original rock may be sedimentary or igneous. Geological age cannot be determined from the photograph.
Uses & applications
Primarily a common decorative or landscaping stone, craft material, or teaching specimen; it has negligible jewelry or commercial value.
Geological facts
The smooth shape records prolonged transport and abrasion, while the muted color may reflect iron-oxide staining or surface weathering.
Field identification & locations
Identify more precisely by examining a fresh broken surface, grain texture, acid reaction, and streak; quartz-rich material resists scratching by steel. Similar pebbles occur in riverbeds, beaches, glacial till, and gravel pits worldwide.
