sedimentary

Rounded pebble, likely quartz-rich sandstone or chert

Indeterminate lithic clast; possibly quartz arenite or microcrystalline quartz (SiO₂)

AI-generated identification · may be incorrect

Small, water-worn, tan-gray pebble with a dull to slightly waxy luster and no visible crystals or cleavage; estimated hardness 6–7 if quartz-rich, with moderate density. The image alone cannot distinguish sandstone from chert confidently.

Identified August 7, 2026More sedimentary →

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At a glance

Common name: Rounded pebble, likely quartz-rich sandstone or chert
Scientific name: Indeterminate lithic clast; possibly quartz arenite or microcrystalline quartz (SiO₂)
Category: sedimentary
Identified: August 7, 2026
Method: Standard

AI Estimated Value

Generally under $1 as an ordinary pebble; approximately $2–$10 if unusually attractive, locality-labeled, or 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

Likely weathered from a sedimentary outcrop and rounded by stream, beach, or glacial transport; its precise geological age and source are indeterminate.

Uses & applications

Primarily a natural pebble or teaching/collecting specimen; not economically valuable at this size, though similar material may be used as aggregate, landscaping stone, or occasionally lapidary rough.

Geological facts

The smooth, subrounded shape records mechanical abrasion during transport. A steel knife or glass-scratch test can help: quartz-rich material commonly scratches glass, while softer sandstone may not.

Field identification & locations

Common in riverbeds, beaches, gravel deposits, and glacial till worldwide. Inspect a fresh break with a hand lens: visible sand grains suggest sandstone; a uniformly fine, waxy interior suggests chert.