sedimentary

Rounded river pebble, likely sandstone or weathered quartz-rich sedimentary rock

Indeterminate siliciclastic pebble; likely quartz–feldspar sandstone, with possible iron-oxide staining

AI-generated identification · may be incorrect

Fine-grained, tan-brown, dull to faintly earthy luster, smoothly water-worn and subrounded; estimated Mohs hardness 5–7, depending on cement and quartz content. No visible crystals, cleavage, or bedding at this scale.

Identified August 26, 2026More sedimentary →

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At a glance

Common name: Rounded river pebble, likely sandstone or weathered quartz-rich sedimentary rock
Scientific name: Indeterminate siliciclastic pebble; likely quartz–feldspar sandstone, with possible iron-oxide staining
Category: sedimentary
Identified: August 26, 2026
Method: Standard

AI Estimated Value

$0–$5 as an individual common pebble; a few dollars per kilogram in bulk

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Likely formed from compacted and cemented sand, then eroded and rounded by river, beach, or glacial transport. Its exact geological age and source cannot be determined from the photograph.

Uses & applications

Commonly used as decorative landscaping gravel, craft material, and aquarium or garden stone; this ordinary pebble has negligible jewelry value.

Geological facts

The rounded shape records abrasion during transport, while the brown coloration commonly reflects iron oxides. A streak, hardness, and acid test would help distinguish sandstone from chert or altered volcanic rock.

Field identification & locations

Common worldwide in streambeds, beaches, and glacial deposits; identify by testing hardness, examining a fresh fracture, and checking whether grains are visible. Approximate value: $0–$5 as an individual specimen, or a few dollars per kilogram in bulk.