sedimentary
Rounded river pebble
Likely quartz-rich sandstone or weathered chert; exact identification requires testing
AI-generated identification · may be incorrectSmall, smooth, subrounded gray-brown pebble with a dull earthy-to-subtle satin luster and possible fine granular texture. Likely Mohs hardness about 6–7 if quartz-rich; cleavage absent and specific gravity roughly 2.5–2.7.
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Physical properties
Small, smooth, subrounded gray-brown pebble with a dull earthy-to-subtle satin luster and possible fine granular texture. Likely Mohs hardness about 6–7 if quartz-rich; cleavage absent and specific gravity roughly 2.5–2.7.
Formation & geological history
Most likely a naturally water-worn clast produced by erosion, transport, and abrasion in a stream, beach, or gravel deposit; its original rock may be sedimentary and could be millions to billions of years old.
Uses & applications
Primarily a curiosity, paperweight, craft stone, or garden decoration; not identifiable as a jewelry-grade gemstone from the photograph.
Geological facts
The rounded shape records prolonged abrasion during transport. Surface pores or pits may reflect weathering, dissolution, or a fine-grained sandstone texture.
Field identification & locations
Check streak, hardness, and reaction to dilute hydrochloric acid: quartz-rich material should not fizz and should scratch glass, while calcite-rich stone fizzes and is softer. Common in river gravels, beaches, and glacial deposits.
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