Rocksday

Dunite

A rock that is more than 90% olivine, bright green inside and tan on the outside.

Dunite specimen
Photo: B.navez, CC BY-SA 3.0, via Wikimedia Commons

How to identify dunite

  • Sugary green olivine throughout.
  • Tan, sandpapery weathered rind.
  • Very heavy.

Often confused with

Where it's found

  • Dun Mountain, New Zealand
  • Twin Sisters, Washington
  • Åheim, Norway

Uses

Foundry sand, refractory material and slag conditioner.

Rock tumbling

Can be tumbled with care.

Did you know?

It's named after Dun Mountain in New Zealand, whose barren slopes look dun-colored.

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