Goethite
Iriyama, Nakanojo city, Agatsuma county, Gunma pref., Japan
IMA approved name
Goethite pseudomorph after a plant

Length: 40 mm. Goethite pseudomorph after a plant. A wood branch was completely replaced by black goethite. It is heavy.
Recovered from a goethite-jarosite deposit formed by bacterial Fe biomineralization from Fe-Sulfate spring water. Formed in less than a million years.
Other localities
- Kobushi Mine (Pneumatolytlic Skarn, replacing Pyrite)
- Chichibu Mine (Hydrothermal Skarn, Reniform)
- Nakatatsu Mine (Hydrothermal Skarn, Reniform)
- Mikawa Mine (Hydrothermal, Acicular)
- Gunma Mine (Bog Iron, replacing Plants)
- Sukayu hot spring (Bog Iron)
- Mount Takeshi (Tuff, replacing Pyrite)