sedimentary

Weathered iron-rich stone, likely ironstone or hematite-bearing chert

Goethite–hematite-rich ironstone; possibly ferruginous chert (FeO(OH)/Fe₂O₃ with silica)

AI-generated identification · may be incorrect

Brown to reddish-black, rounded and weathered, with earthy to submetallic luster and no visible cleavage; typical hardness is about 5–6.5 Mohs and specific gravity roughly 3–5, depending on iron content.

Identified August 22, 2026More sedimentary →

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At a glance

Common name: Weathered iron-rich stone, likely ironstone or hematite-bearing chert
Scientific name: Goethite–hematite-rich ironstone; possibly ferruginous chert (FeO(OH)/Fe₂O₃ with silica)
Category: sedimentary
Identified: August 22, 2026
Method: Standard

AI Estimated Value

Typically $1–$10 as an ordinary specimen; attractive polished or strongly magnetic pieces may sell for about $10–$30.

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 by chemical precipitation or replacement in iron-rich sedimentary environments, then rounded by transport and oxidation; precise age and origin cannot be determined from the image alone.

Uses & applications

Common ironstone has limited commercial value but may be used as iron ore, aggregate, or a teaching/collecting specimen; it is generally not gem quality.

Geological facts

The rusty brown color reflects oxidized iron minerals such as goethite and hematite. A reddish-brown streak on unglazed porcelain and attraction to a strong magnet can help assess its composition.

Field identification & locations

Common in weathered iron deposits, stream gravels, and lateritic soils worldwide, especially Australia, Brazil, India, and the Lake Superior region. A heavy feel, rusty streak, and possible magnetic response distinguish it from ordinary brown river stone.