Rocksday

Siderite

An iron carbonate forming brown, often curved rhomb-shaped crystals.

Siderite specimen
Photo: DerHexer, Wikimedia Commons, CC BY-SA 4.0, via Wikimedia Commons

How to identify siderite

  • Tan to dark brown rhombs with curved faces.
  • Fizzes in warm acid.
  • Heavier than calcite.

Often confused with

Where it's found

  • Panasqueira, Portugal
  • Cornwall, England
  • Minas Gerais, Brazil
  • Colorado

Uses

Iron ore.

Rock tumbling

Not suitable for tumbling.

Did you know?

Its name comes from Greek sideros, 'iron'.

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