Rock Identifier
Red Ochre (Hematite-rich Clay) (Limonitic/Hematitic Claystone (Fe2O3 with clay minerals)) — Sedimentary
Sedimentary

Red Ochre (Hematite-rich Clay)

Limonitic/Hematitic Claystone (Fe2O3 with clay minerals)

Hardness: 1-5 (Mohs scale, varies by clay content); Color: Rusty red to earthy orange; Luster: Dull/Earthy; Crystal Structure: Amorphous or microcrystalline; Cleavage: None/Fragmental; Specific Gravity: 2.5-4.0

Hardness
1-5 (Mohs scale, varies by clay content)
Color
Rusty red to earthy orange
Luster
Dull/Earthy
Identified More sedimentary

Identify your own rocks.

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

Physical properties

Hardness: 1-5 (Mohs scale, varies by clay content); Color: Rusty red to earthy orange; Luster: Dull/Earthy; Crystal Structure: Amorphous or microcrystalline; Cleavage: None/Fragmental; Specific Gravity: 2.5-4.0

Formation & geological history

Formed through the chemical weathering of iron-rich silicate minerals or the precipitation of iron oxides in sedimentary environments. Common in tropical or temperate weathering crusts (laterites) and fossilized soils (paleosols).

Uses & applications

Historically used as a pigment for cave paintings; currently used in the manufacture of paint fillers, cosmetics, ceramics, and as a polishing agent (jeweler's rouge).

Geological facts

Ochre is one of the oldest pigments used by humans, with evidence in archaeological sites dating back over 75,000 years. It is chemically stable and does not fade over time.

Field identification & locations

Identify in the field by its distinct reddish-orange stain on skin/hands and its brittle, crumbly texture. Found globally in iron-rich sedimentary basins and weathered volcanic terrains. Collectors look for high purity and deep color saturation.