mineral

Weathered iron-rich rock, likely limonite/goethite-bearing basalt or ironstone

Limonite (hydrated iron oxides; chiefly goethite, FeO(OH)) with probable silicate host rock

AI-generated identification · may be incorrect

Hardness about 4–5.5 Mohs; earthy yellow-brown to dark gray-black, dull to submetallic luster, massive and non-cleavable. The rusty yellow coating suggests iron-oxide weathering; exact identification requires streak, magnetism, and fresh-break testing.

Identified August 14, 2026More mineral →

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At a glance

Common name: Weathered iron-rich rock, likely limonite/goethite-bearing basalt or ironstone
Scientific name: Limonite (hydrated iron oxides; chiefly goethite, FeO(OH)) with probable silicate host rock
Category: mineral
Identified: August 14, 2026
Method: Standard

AI Estimated Value

Typically $1–$15 as an unidentified common specimen; attractive locality-labeled pieces may sell for $20–$50.

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

Forms by oxidation and hydration of iron-bearing minerals near the surface, commonly developing as a weathering rind or ironstone. It may be geologically young relative to its host rock and is not reliably age-diagnostic from the image.

Uses & applications

Iron oxides are mined as iron ore and used in pigments; otherwise, this type of specimen has mainly educational or modest collecting value.

Geological facts

Limonite is a field term rather than a single precisely defined mineral species, commonly representing mixtures dominated by goethite and related iron oxides.

Field identification & locations

Common in weathered basalt, gossans, soil horizons, and iron-rich sediments worldwide. A yellow-brown streak, reddish-brown powder, and possible weak magnetism support iron oxides; a magnet and streak plate would help distinguish it from sulfides or slag.