sedimentary

Polished sedimentary pebble, likely sandstone or quartzite

Quartz-rich sandstone (SiO₂-dominant), possibly weakly metamorphosed quartzite

AI-generated identification · may be incorrect

Rounded and smoothed by abrasion; tan-pink, fine-grained, and dull to subtly sugary in luster. Quartz-rich material is typically Mohs 6–7, with no obvious cleavage and a granular texture; the image alone cannot confirm exact composition.

Identified September 19, 2026More sedimentary →

Explore Polished sedimentary pebble, likely 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: Polished sedimentary pebble, likely sandstone or quartzite
Scientific name: Quartz-rich sandstone (SiO₂-dominant), possibly weakly metamorphosed quartzite
Category: sedimentary
Identified: September 19, 2026
Method: Standard

AI Estimated Value

Approximately $2–$15 for a common polished pebble; $20–$50 if unusually attractive, labeled, or from a notable locality.

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 formed from cemented quartz sand, then naturally or artificially rounded and polished; if quartzite, it was recrystallized during metamorphism. The geological age is indeterminate from the photograph.

Uses & applications

Used mainly as a decorative or collecting stone, worry stone, or craft piece; sandstone and quartzite are also used as building stone, aggregate, and paving material.

Geological facts

The nearly circular shape and uniformly smooth surface suggest tumbling or deliberate shaping rather than an unmodified outcrop fragment. A streak test, hardness test, and close inspection of grain boundaries would distinguish sandstone from quartzite.

Field identification & locations

Common in river gravels and sedimentary terrains worldwide. Quartz-rich specimens resist scratching by steel and do not fizz with dilute hydrochloric acid; avoid destructive tests if it is a valued polished piece.