mineral

Limonite with Hematite

Limonite (FeO(OH)·nH2O) and Hematite (Fe2O3)

Hardness: 4-5.5; Color: Yellowish-brown to reddish-brown; Luster: Dull or earthy; Crystal Structure: Amorphous/microcrystalline; Streak: Yellow-brown for limonite/Red-brown for hematite.

Hardness: 4-5
Color: Yellowish-brown to reddish-brown
Luster: Dull or earthy

Identified April 10, 2026More mineral →

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Physical properties

Hardness: 4-5.5; Color: Yellowish-brown to reddish-brown; Luster: Dull or earthy; Crystal Structure: Amorphous/microcrystalline; Streak: Yellow-brown for limonite/Red-brown for hematite.

Formation & geological history

Formed as a secondary mineral through the weathering and oxidation of iron-rich minerals such as pyrite, magnetite, or siderite. Common in sedimentary environments and oxidized zones of ore deposits.

Uses & applications

Historically used as an iron ore; currently used as a natural earth pigment (yellow ochre/burnt sienna) and for geological study.

Geological facts

Limonite is not a true mineral but a generic term for several hydrated iron oxides. It was once a primary source of iron for ancient civilizations and is the main colorant in many soils.

Field identification & locations

Identify in the field by its characteristic 'rust' color and earthy texture. A simple streak test on unglazed porcelain will yield a yellowish-brown or red mark which is diagnostic for these iron oxides.

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