sedimentary

Weathered iron-rich river pebble

Ferruginous sandstone or ironstone; composition likely quartz with iron oxides (hematite/goethite)

AI-generated identification · may be incorrect

Hardness approximately 5–7 Mohs; brown-orange, dull to earthy luster, fine-grained and rounded, with no visible cleavage. The color and small pits suggest iron-oxide cement or weathering.

Identified August 26, 2026More sedimentary →

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At a glance

Common name: Weathered iron-rich river pebble
Scientific name: Ferruginous sandstone or ironstone; composition likely quartz with iron oxides (hematite/goethite)
Category: sedimentary
Identified: August 26, 2026
Method: Standard

AI Estimated Value

About $1–$10 for an ordinary pebble; $10–$30 if unusually attractive, locality-specific, or sold as a labeled geological 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

Hardness approximately 5–7 Mohs; brown-orange, dull to earthy luster, fine-grained and rounded, with no visible cleavage. The color and small pits suggest iron-oxide cement or weathering.

Formation & geological history

Likely a naturally rounded sedimentary fragment shaped by stream or shoreline abrasion; iron oxidation produced the rusty coloration over geological time, commonly during the Cenozoic or earlier depending on its source.

Uses & applications

Usually a decorative or teaching specimen; ferruginous sandstone may be used locally as building stone, while ironstone can be an iron ore when sufficiently rich.

Geological facts

Iron oxides commonly stain otherwise pale quartz-rich rocks red, orange, or brown. The smooth shape indicates transport, whereas the porous edge may reflect weathering or dissolution of softer grains.

Field identification & locations

Identify it by its rusty color, granular texture, rounded surface, and possible red-brown streak; a magnet test may show weak attraction if magnetite is present. Common in stream beds, beaches, glacial deposits, and weathered outcrops worldwide.