sedimentary

Rounded iron-rich concretion or weathered sandstone pebble

Goethite/hematite-bearing sandstone or limonite concretion; exact identification requires testing

AI-generated identification · may be incorrect

Opaque, rounded, tan-orange to brown, dull earthy luster with a fine granular surface. Likely hardness about 4–6 Mohs and moderate-to-high density; no visible crystal cleavage.

Identified August 28, 2026More sedimentary →

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At a glance

Common name: Rounded iron-rich concretion or weathered sandstone pebble
Scientific name: Goethite/hematite-bearing sandstone or limonite concretion; exact identification requires testing
Category: sedimentary
Identified: August 28, 2026
Method: Standard

AI Estimated Value

Typically $1–$10 as an unverified common specimen; potentially $10–$30 if confirmed as an attractive, locality-specific concretion.

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

Opaque, rounded, tan-orange to brown, dull earthy luster with a fine granular surface. Likely hardness about 4–6 Mohs and moderate-to-high density; no visible crystal cleavage.

Formation & geological history

Probably formed by sediment cemented with iron oxides/hydroxides, then rounded by transport or weathering; age depends on its source formation and cannot be determined from the photograph.

Uses & applications

Usually a curiosity or teaching specimen; iron-rich sandstone may be used locally as aggregate or building stone, but this individual has negligible industrial value.

Geological facts

The orange-brown color commonly comes from limonite/goethite and hematite coatings or cement. Its unusually smooth shape may reflect stream abrasion, shoreline action, or natural concretion growth.

Field identification & locations

Common in weathered sedimentary terrains and stream gravels worldwide. A streak test on unglazed porcelain, magnetism test, acid reaction, and hardness test can distinguish ironstone from sandstone, slag, or other rounded debris.