sedimentary/metamorphic

Rounded river pebbles, likely quartz-rich sandstone or quartzite

Indeterminate quartz–feldspar rock; possible quartzite or arkosic sandstone

AI-generated identification · may be incorrect

Visible stones are water-rounded, tan to reddish-brown, fine- to medium-grained, and mostly dull to weakly earthy-lustrous. Quartz-rich rocks typically have Mohs hardness 6.5–7, no obvious cleavage, and specific gravity about 2.6–2.7; the image is insufficient to confirm texture or mineral percentages.

Identified September 12, 2026More sedimentary/metamorphic →

Explore Rounded river pebbles, likely quartz-rich sandstone or quartzite in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

At a glance

Common name: Rounded river pebbles, likely quartz-rich sandstone or quartzite
Scientific name: Indeterminate quartz–feldspar rock; possible quartzite or arkosic sandstone
Category: sedimentary/metamorphic
Identified: September 12, 2026
Method: Standard

AI Estimated Value

About $1–$10 per common landscaping or craft specimen; usually under $20 unless provenance, unusual patterning, or gem-quality material is established.

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 transported and rounded by stream or beach abrasion, derived from weathered quartz-bearing bedrock. The original material may be sedimentary sandstone later metamorphosed into quartzite; age cannot be determined visually.

Uses & applications

Commonly used as landscaping, drainage, aggregate, decorative stone, and craft material; generally little jewelry or collector value unless unusually patterned or verified as a specific stone.

Geological facts

The large reddish pebble may contain iron-oxide staining, while pale flecks could be quartz or feldspar. Rounded shape indicates substantial abrasion during transport.

Field identification & locations

Test a fresh edge for hardness: quartz-rich material scratches glass and does not fizz with dilute hydrochloric acid. A hand lens can distinguish fused quartz grains of quartzite from visibly cemented grains of sandstone; likely locations are riverbeds, gravel bars, and beaches.