Aegirine
Odaira, Tono village, Iwaki city, Fukushima pref., Japan
Field of view: 30 mm. Aegirine associated with braunite. The brown vein is aegirine composed of fibers vertical to the vein. The massive brown host is aggregate of fine braunite crystals, and the white parts are quartz. The two black veins with an earthy luster are probably manganese dioxide.
Recovered from a chert-hosted bedded manganese deposit subjected to Epidote-Amphibolite facies regional metamorphism and contact metamorphism by granite.
Aegirine from this location was described in 1975.