Rocksday

Limonite

A rusty mixture of hydrated iron oxides, not a single mineral. It forms where iron-rich rocks weather.

Limonite specimen
Photo: Robert M. Lavinsky, CC BY-SA 3.0, via Wikimedia Commons

How to identify limonite

  • Rusty yellow-brown, earthy masses.
  • Yellowish-brown streak.
  • Often fills holes or replaces pyrite cubes.

Often confused with

Where it's found

  • Bogs and weathered iron deposits worldwide

Uses

Historic iron ore (bog iron) and yellow ochre pigment.

Rock tumbling

Not suitable for tumbling.

Did you know?

Vikings and early medieval smiths smelted iron from limonite dug out of bogs.

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