mineral

Iron-rich weathered pebble

Likely limonite/goethite-bearing ferruginous rock; exact identification requires testing

AI-generated identification · may be incorrect

Small rounded brown-black pebble with dull to earthy luster and no visible crystals; likely hardness about 4–6 Mohs and moderate-to-high density. Color and surface suggest iron oxides coating or cementing a silicate rock.

Identified August 15, 2026More mineral →

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Physical properties

Formation & geological history

Formed by weathering and oxidation of iron-bearing minerals in soil, stream sediment, or exposed bedrock; age cannot be determined from the photograph.

Uses & applications

Primarily a natural curiosity or teaching specimen; iron-oxide-rich material can serve as pigment or iron ore, though this piece has no practical commercial value.

Geological facts

Limonite is a mixture of hydrated iron oxides rather than a single precisely defined mineral, while goethite is a crystalline iron oxyhydroxide. A reddish-brown streak on unglazed porcelain would support an iron-oxide identification.

Field identification & locations

Common in soils, stream gravels, and weathered outcrops worldwide. Check streak, magnetism, density, and hardness; the photograph alone cannot distinguish it confidently from a dark basalt or ordinary iron-stained chert.