sedimentary/metamorphic

Smooth river pebble, likely quartz-rich sandstone or quartzite

Probable quartz arenite (sandstone) or quartzite; mainly SiO₂ with minor iron-bearing minerals

AI-generated identification · may be incorrect

Rounded, fine-grained, dull to faintly satin luster; tan-brown from iron staining. Likely Mohs hardness 6–7, massive with no visible cleavage; exact identification requires a hardness and acid test.

Identified September 3, 2026More sedimentary/metamorphic →

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At a glance

Common name: Smooth river pebble, likely quartz-rich sandstone or quartzite
Scientific name: Probable quartz arenite (sandstone) or quartzite; mainly SiO₂ with minor iron-bearing minerals
Category: sedimentary/metamorphic
Identified: September 3, 2026
Method: Standard

AI Estimated Value

About $1–$10 as an ordinary collected pebble; up to $10–$30 if unusually attractive, polished, or provenance-labeled.

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

Rounded by prolonged water abrasion in a stream or river; if quartzite, it began as sandstone and recrystallized during metamorphism. Age cannot be determined visually and depends on its source bedrock.

Uses & applications

Usually decorative or educational, with little commercial value; suitable for landscaping, crafts, and rock collections rather than jewelry or construction.

Geological facts

The smooth shape indicates transport and abrasion, while the uniform texture suggests a fine-grained silicate rock rather than a crystal-rich igneous rock.

Field identification & locations

Test an inconspicuous area: quartz-rich material scratches glass and does not fizz with dilute hydrochloric acid; sandstone may feel slightly gritty and scratch less consistently. Common in streambeds worldwide.