Rhodonite
Ashio village, Nikko city, Tochigi pref., Japan
Source for manganese
Field of view: 100 mm. Grayish-brown rhodonite. The massive grayish-brown parts are rhodonite. The grayish-brown color is due to Fe replacing Mn. The massive group of coarse reddish-brown crystals is pyrosmalite-(Mn). The white veins are quartz, and the massive black parts are the host chert.
Recovered from a chert-hosted bedded manganese deposit subjected to Albite-Epidote-hornfels facies contact metamorphism.
Spessartine from this location was described in 1954.
Other localities
- Hagidaira Mine (Mn skarn, Tabular)
- Higashizawa Mine (Mn skarn, Prismatic)
- Kyurazawa Mine (Mn skarn, Fe-rich)
- Mogurazawa Mine (Mn skarn, Purple and Pink)
- Takanosu Mine (Mn skarn, Banded)
- Kurokawa Mine (Mn skarn, Massive)
- Kanoiri Mine (Mn skarn, Massive)
- Gozaisho Mine (Bedded Mn, EA facies)
- Kiyokawa Mine (Bedded Mn, Zeo facies)