igneous
Rounded quartz-rich river pebble
Likely quartz-bearing rock; exact lithology cannot be determined from the photograph
AI-generated identification · may be incorrectBrown and gray, mottled, with a dull to slightly glossy surface and rounded, water-worn shape. Quartz, if present, has Mohs hardness 7 and a hexagonal crystal structure; the pebble’s hardness and composition cannot be confirmed visually.
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Physical properties
Brown and gray, mottled, with a dull to slightly glossy surface and rounded, water-worn shape. Quartz, if present, has Mohs hardness 7 and a hexagonal crystal structure; the pebble’s hardness and composition cannot be confirmed visually.
Formation & geological history
Likely weathered from a quartz-bearing source rock and rounded during transport in water. Its geological age and original rock type are not identifiable from the image.
Uses & applications
Primarily a natural collectible or decorative pebble; quartz-rich rocks may also be used as aggregate or building stone.
Geological facts
The smooth shape and rounded edges are consistent with prolonged abrasion during transport, though tumbling is another possibility.
Field identification & locations
Look for glassy quartz grains, mineral boundaries, and a hard surface that resists scratching by steel. Common in riverbeds and beaches; a photo alone is insufficient for a precise identification.
