sedimentary

Weathered iron-rich rock, possibly banded iron formation

Hematite–goethite-rich ironstone; possible BIF (Fe₂O₃/FeO(OH) with quartz)

AI-generated identification · may be incorrect

Dark gray to rusty brown, earthy to submetallic luster, irregular fracture, and porous weathering cavities; likely Mohs 5–6, with locally softer earthy zones. The image suggests iron oxides staining a quartz- or chert-rich matrix, but mineral identification is not definitive from appearance alone.

Identified August 23, 2026More sedimentary →

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At a glance

Common name: Weathered iron-rich rock, possibly banded iron formation
Scientific name: Hematite–goethite-rich ironstone; possible BIF (Fe₂O₃/FeO(OH) with quartz)
Category: sedimentary
Identified: August 23, 2026
Method: Standard

AI Estimated Value

Approximately $5–$30 for a common weathered specimen; $30–$150 or more if it shows strong banding, unusual texture, or an identified 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 by chemical precipitation of iron minerals and silica in ancient marine environments, then altered and oxidized during weathering; many BIFs are Precambrian, roughly 2.5–1.8 billion years old. It could also be a younger ironstone or weathered iron-rich metamorphic rock.

Uses & applications

Iron ore is mined for steel production when sufficiently enriched; attractive pieces are collected as mineral specimens or used decoratively. This specimen appears more suitable for collecting than industrial ore.

Geological facts

Hematite commonly produces a reddish-brown streak, while magnetite-bearing portions may attract a magnet. Rust-colored surfaces reflect oxidation of iron-bearing minerals.

Field identification & locations

Common in Australia, Brazil, India, South Africa, Ukraine, and North America. Test streak on unglazed porcelain, magnetism, and hardness; a laboratory assay or thin section is needed for confident classification.