mineral
Iron-rich weathered pebble (likely limonite/goethite-bearing rock)
Limonite mixture, commonly dominated by goethite (FeO(OH)) and hematite (Fe₂O₃)
AI-generated identification · may be incorrectOrange-brown, dull to earthy luster, fine-grained and rounded; apparent hardness about 4–6 Mohs, with no visible cleavage or crystals. The coloration suggests hydrated iron oxides coating or replacing a denser host rock.
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Physical properties
Orange-brown, dull to earthy luster, fine-grained and rounded; apparent hardness about 4–6 Mohs, with no visible cleavage or crystals. The coloration suggests hydrated iron oxides coating or replacing a denser host rock.
Formation & geological history
Formed by oxidation and weathering of iron-bearing minerals, often in soils, lateritic zones, or weathered sulfide deposits; usually geologically young as a surface alteration product, though the source rock may be ancient.
Uses & applications
Commonly collected as an iron-oxide specimen; similar material has historically been used as iron ore and ochre pigment, but this small pebble has little industrial value.
Geological facts
Limonite is not a single mineral but a variable mixture of hydrated iron oxides. It may leave a yellow-brown streak and often forms rusty coatings around other rocks.
Field identification & locations
Likely locations include weathered iron-rich terrains worldwide. Test with an unglazed tile for a yellow-brown streak, inspect for magnetic response, and use a hardness test; image-only identification cannot exclude an iron-stained sandstone or basalt.
