mineral

Yellow Ochre / Limonite

Limonite (Hydrated Iron(III) Oxide-Hydroxide, FeO(OH)·nH2O)

Hardness: 4.0-5.5 (Mohs scale), Color: Yellow to brownish-yellow, Luster: Dull or earthy, Crystal Structure: Amorphous (microcrystalline), Cleavage: None, Specific Gravity: 2.7-4.3

Hardness: 4

Identified April 4, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 4.0-5.5 (Mohs scale), Color: Yellow to brownish-yellow, Luster: Dull or earthy, Crystal Structure: Amorphous (microcrystalline), Cleavage: None, Specific Gravity: 2.7-4.3

Formation & geological history

Formed as a secondary material through the oxidation or chemical weathering of iron-rich minerals such as pyrite, magnetite, and siderite. Often found in hydrothermal veins or bog deposits.

Uses & applications

Major source of iron ore, historically used as a primary pigment (ochre) for paints and dyes. Currently used in industrial coloring and soil conditioners.

Geological facts

Yellow ochre is one of the oldest pigments used by humans, seen in cave paintings dating back over 30,000 years. It is chemically very similar to rust.

Field identification & locations

Identify by its distinctive mustard-yellow or 'ochre' streak on a porcelain plate and its earthy, non-crystalline appearance. Commonly found in weathered iron-bearing rocks or near marshes.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral