mineral
Limonite
FeO(OH)•nH2O
Hardness: 4 to 5.5 on the Mohs scale, Color: Yellowish-brown, brown, to dark brown, Luster: Earthy, submetallic, or silky, Crystal structure: Amorphous or microcrystalline (pseudomorphic), Cleavage: None, Specific gravity: 2.7 to 4.3
- Hardness
- 4 to 5
Identified More mineral →
Explore Limonite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 4 to 5.5 on the Mohs scale, Color: Yellowish-brown, brown, to dark brown, Luster: Earthy, submetallic, or silky, Crystal structure: Amorphous or microcrystalline (pseudomorphic), Cleavage: None, Specific gravity: 2.7 to 4.3
Formation & geological history
Formed through the oxidation and weathering of iron-rich minerals and rocks (such as pyrite, magnetite, and hematite) in low-temperature aqueous environments, often in bogs, soils, and weathering crusts.
Uses & applications
Used historically as a pigment (ochre), as a minor ore of iron, and as a collector's specimen.
Geological facts
Limonite is not a single distinct mineral, but rather a mixture of related hydrated iron oxides and hydroxides, most commonly goethite, lepidocrocite, and jarosite.
Field identification & locations
Easily identified by its characteristic yellowish-brown to brownish-orange streak and earthy appearance. Commonly found worldwide in oxidized zones of iron ore deposits.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Soil with Mineral Detritus and Quartz Fragments
Regolith / Silicate Mineral Aggregate
sedimentary
Limonite / Goethite (Iron Ore Mineral nodule)
FeO(OH)·nH2O / FeO(OH)
mineral
Septarian Pebble
Septarian nodule / Concretion
sedimentary
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral
Schist
Schist
Metamorphic