sedimentary

Tumbled sandstone or quartz-rich sedimentary pebble

Likely quartz–feldspar sandstone (SiO₂-rich clastic rock); exact identification requires testing

AI-generated identification · may be incorrect

Smooth, rounded, pale tan, matte to weakly waxy surface with subtle grains and fractures. Likely Mohs hardness 6–7 if quartz-rich; nonmetallic luster, no obvious cleavage, low-to-moderate density (~2.3–2.7 g/cm³).

Identified August 14, 2026More sedimentary →

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At a glance

Common name: Tumbled sandstone or quartz-rich sedimentary pebble
Scientific name: Likely quartz–feldspar sandstone (SiO₂-rich clastic rock); exact identification requires testing
Category: sedimentary
Identified: August 14, 2026
Method: Standard

AI Estimated Value

Typically $1–$10 as a common collected pebble; up to about $20 if unusually attractive, polished, or sold as a specimen.

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

Formed from cemented sand grains deposited in an ancient river, beach, dune, or other sedimentary environment, then naturally or mechanically rounded. Its precise geological age cannot be determined from the photograph.

Uses & applications

Common sandstone is used for building stone, paving, landscaping, and aggregate; attractive rounded pieces are sold as décor or lapidary material. Usually little monetary value.

Geological facts

The uniform rounding strongly suggests transport by water or tumbling. A vinegar test is generally uninformative unless carbonate cement is present.

Field identification & locations

Common in riverbeds, beaches, deserts, and gravel deposits worldwide. Inspect with a loupe for visible quartz grains; a streak test, hardness test, and dilute hydrochloric acid test can distinguish sandstone from limestone or softer altered rock.