Autunite
Hanazono Mine
Hanazono, Hanakawa village, Kita-Ibaraki city, Ibaraki pref., Japan
Field of view: 10 mm. Autunite associated with biotite. The hexagonal platy black crystal at the center is biotite. The surrounding yellow crust around the biotite crystal is autunite. There are very fine platy crystals of autunite at the top of the biotite crystal. The white basement is feldspar.
Recovered from an NYF-Andalusite pegmatite associated with S-type (Ilmenite-series) granite.
Autunite from this location was described in 1977.