Bismuthinite
Agenosawa Mine
Nanokaichi, Kita-Akita city, Akita pref., Japan
Source for bismuth
Field of view: 30 cm. Bismuthinite associated with pyrite. The silver-white prisms are bismuthinite exhibiting perfect cleavage parallel to the prism. The yellow matrix around bismuthinite is aggregate of fine pyrite.
Recovered from a sulfide vein of a moderate-temperature hydrothermal deposit associated with dacite of a caldera complex. Formed in the late Miocene (10 Ma).
Bismuthinite from this location was described in 1972.