Mugikusa Pass
Kami, Sakuho city, Minami-Saku county, Nagano pref., Japan
Occurrence
Minerals associated with Inagodake Lavas of Northern Yatsugatake volcanoes.

Outcrop of obsidian, a part of rhyolite of Inagodake Lavas. The flow structure is clear observed. Massive dark gray to black parts are obsidian. Pink to white striations are mainly composed of cristobalite. The brown parts are soil.
Reported Minerals
- Cristobalite
- Obsidian
Mineral Assemblages
- Obsidian(Host) - Cristobalite