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term · Oxides & Hydroxide

Limonite

FeO(OH)·nH₂O

Field term for mixed iron oxyhydroxides — mainly goethite — not a single species.

Hardness4–5.5
Crystal systemAmorphous
ClassOxides & Hydroxide
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Limonite specimen

A geode with Prehnite-Laumontite crystals Note: The provenance and correct determination of this mineral is disputed. According to User:Archaeodontosaurus it is — Photo: CEphoto, Uwe Aranas · CC BY-SA 4.0

Limonite

Also known as: Brown iron ore, Rust.

The catch-all name for mixed hydrated iron oxides — the yellow-brown 'bog iron' and gossan material, not a true species.

Intro adapted from Wikipedia (CC BY-SA).

Limonite is a catalogue entry, with the chemical formula FeO(OH)·nH₂O.

It crystallizes in the amorphous crystal system.

Key properties: Mohs hardness 4–5.5; typically brown or yellow.

Collections: Everyday Minerals, Metals & Native Elements.

Index entry. This entry combines official IMA/RRUFF species data with published physical-property data and a Wikipedia introduction — a full written entry hasn’t been published yet. Browse more L minerals or help write this entry.