mineral

Iron-rich brown rock, possibly limonite/goethite

Limonite (hydrated iron oxides; commonly goethite, FeO(OH), with hematite)

AI-generated identification · may be incorrect

Brown to reddish-brown, earthy to dull/submetallic luster, irregular massive texture, and no visible crystal faces or cleavage. Estimated Mohs hardness 4–5.5; typically dense and may leave a yellow-brown streak.

Identified September 11, 2026More mineral →

Explore Iron-rich brown rock, possibly limonite/goethite in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Forms by weathering and oxidation of iron-bearing minerals, often as a residual soil or cavity coating; its exact geological age cannot be determined from the image. The specimen may also be iron-stained quartz or another iron-rich rock.

Uses & applications

Used historically as an iron ore and natural ochre pigment; attractive pieces are collected, but it is generally not used for jewelry or construction.

Geological facts

“Limonite” is a field and commercial name rather than one pure mineral, because it is a mixture of hydrated iron oxides. Goethite-rich specimens commonly form botryoidal or earthy masses.

Field identification & locations

Look for a yellow-to-brown streak, high density, rusty coloration, and attraction only if magnetite is present. Common in weathered iron deposits worldwide; testing streak, hardness, and magnetism would improve identification.