sedimentary

Weathered iron-rich rock, likely limonite/goethite-bearing sandstone or laterite

Hydrated iron oxides, chiefly limonite (FeO(OH)·nH₂O) and goethite (α-FeO(OH)), possibly cementing sandstone

AI-generated identification · may be incorrect

Rusty yellow-brown, earthy to dull luster, porous and rough, with no obvious crystals or cleavage; estimated Mohs hardness 3–5, specific gravity about 2.7–4.3. The pale angular inclusion may be quartz or feldspar.

Identified August 20, 2026More sedimentary →

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At a glance

Common name: Weathered iron-rich rock, likely limonite/goethite-bearing sandstone or laterite
Scientific name: Hydrated iron oxides, chiefly limonite (FeO(OH)·nH₂O) and goethite (α-FeO(OH)), possibly cementing sandstone
Category: sedimentary
Identified: August 20, 2026
Method: Standard

AI Estimated Value

Typically $1–$10 as an ordinary specimen; $10–$30 if unusually vivid, locality-labeled, or associated with attractive quartz.

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 intense weathering and oxidation of iron-bearing minerals, concentrating hydrated iron oxides in soil or porous sediment; age cannot be determined from the image. It may represent laterite, ironstone, or ferruginous sandstone.

Uses & applications

Iron-rich material can be an iron ore when sufficiently concentrated, and similar rocks are used as pigment or decorative specimens; this example appears primarily collectible rather than industrial grade.

Geological facts

Limonite is a field term for a mixture of hydrated iron oxides rather than one precisely defined mineral. Yellow-brown streak and earthy texture commonly distinguish it from metallic hematite or magnetite.

Field identification & locations

Check for a yellow-to-brown streak on unglazed ceramic, attraction to a magnet, and reaction to dilute acid; a gritty texture suggests sandstone. Common in weathered tropical soils, sedimentary ironstone, and oxidized ore zones worldwide.