sedimentary

Iron-rich rock fragment (possibly ironstone or limonite/goethite)

Likely ironstone composed largely of goethite/limonite; image alone cannot confirm

AI-generated identification · may be incorrect

Brown, earthy to dull luster, irregular and apparently fine-grained; hardness and specific gravity cannot be reliably determined from the image. Ironstone is commonly dense and may leave a rusty-brown streak.

Identified September 28, 2026More sedimentary →

Explore Iron-rich rock fragment (possibly ironstone or 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

Iron-rich sediment or weathered rock can concentrate and cement iron oxides over geological time; ironstone forms in varied sedimentary environments. Exact age and origin are not identifiable from appearance alone.

Uses & applications

Ironstone has historically served as iron ore where iron content is sufficient; small fragments are mainly collected or used for teaching.

Geological facts

Limonite is a mixture of hydrated iron oxides rather than a single mineral, while goethite is a defined iron oxyhydroxide mineral.

Field identification & locations

The specimen appears to be a small, rough brown geological fragment, but identification would benefit from a fresh streak, hardness test, and density or mineral analysis. Iron-rich rocks occur worldwide.