Omphacite
Higashi-Chichibu city, Chichibu county, Saitama pref., Japan
Vein width: 10 mm. A vein of omphacite. The grayish-green fibers vertical to the vein are omphacite. The massive grayish-green host is metamorphosed tuff. The thin white bed between the host and omphacite vein is albite.
Recovered from an omphacite vein in basaltic tuff subjected to Pumpellyite-Actinolite facies metamorphism. Formed in the Late Cretaceous (100 Ma).
Omphacite from this location was described in 1964.
Other localities
- Kaiya (PA facies, Fibrous)
- Mt. Akaiwa (Eclogite, Fibrous)