sedimentary

Tumbled river pebble, likely fine-grained sandstone or mudstone

Indeterminate lithic clast; possibly quartz-rich sandstone or siltstone

AI-generated identification · may be incorrect

Olive-brown, rounded and smoothly weathered, with dull earthy luster and subtle layering; likely hardness about 5–7 if sandstone, or 3–5 if mudstone. No visible crystals or cleavage; density likely ~2.3–2.7 g/cm³.

Identified August 16, 2026More sedimentary →

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At a glance

Common name: Tumbled river pebble, likely fine-grained sandstone or mudstone
Scientific name: Indeterminate lithic clast; possibly quartz-rich sandstone or siltstone
Category: sedimentary
Identified: August 16, 2026
Method: Standard

AI Estimated Value

Usually under $1–$5 as an ordinary pebble; perhaps $5–$20 if unusually attractive, provenance-specific, or artistically polished.

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

A sedimentary fragment lithified from compacted sand or silt, then rounded by stream or beach abrasion; its precise geological age and provenance cannot be determined from the image.

Uses & applications

Primarily a curiosity, worry stone, craft piece, or low-value collectible; similar stone may be used as aggregate or building material.

Geological facts

The smooth shape indicates prolonged abrasion in moving water or sediment, while the faint bands may reflect original bedding or mineral staining.

Field identification & locations

Common in river gravels and beaches worldwide. Test streak, hardness, and acid reaction; a hand lens may reveal quartz grains, distinguishing sandstone from finer mudstone.