Spessartine
Wada, Nagawa city, Chiisagata county, Nagano pref., Japan
This locality is closed to collecting.
Center crystal: 10 mm. Dispatched garnet crystals of chemical composition near the boundary between spessartine and almandine. Both spessartine and almandine were identified by the strict chemical analysis. The crystal is based on dodecahedron. The opaque white part on the left crystal is the host rhyolite. It is considered that garnet grew from vapor during solidification of rhyolite lava.
Recovered from vesicules of rhyolite lava. Formed in the early Pleistoene (1 Ma).
Garnet from this location was described in 1885, and was designated the prefectural mineral of Nagano in 2016 by the Geological Society of Japan.
Other localities
- Wada pass (Rhyolite, Euhedral)
- Hagidaira mine (Mn skarn, White)
- Kyurazawa mine (Mn skarn, Euhedral)
- Oashi mine (Mn skarn, Vein)
- Taguchi mine (Bedded Mn, AM facies)
- Gozaisho mine (Bedded Mn, EA facies)