sedimentary

Weathered iron-rich concretion or laterite fragment

Ferruginous concretion, likely goethite/limonite (hydrated iron oxides) in a clay-rich matrix

AI-generated identification · may be incorrect

Yellow-brown to rusty, earthy and dull, with irregular porous surfaces and darker iron-stained patches. Likely hardness about 4–6 Mohs, no obvious cleavage, and relatively high density; exact properties require testing.

Identified August 11, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed when iron-bearing groundwater precipitated goethite and limonite within weathered soil or sediment, commonly in tropical lateritic environments. Its precise age cannot be determined from the photograph.

Uses & applications

Usually a low-value geological curiosity; iron-rich laterite can be an iron ore, road aggregate, or building material, though this small specimen has no practical industrial value.

Geological facts

The rounded, knobby shape and ochre coloration are typical of ironstone concretions, but the image alone cannot exclude weathered slag or a clay-rich rock.

Field identification & locations

Look for a yellow-brown streak, attraction to a strong magnet if magnetite is present, and increased density compared with ordinary soil. Common in tropical weathering zones, Australia, India, Africa, and parts of the Americas.