Posnjakite
Naka-Okorogara, Nikko city, Tochigi pref., Japan
Field of view: 5 mm. Crystals of posnjakite. The platy light blue crystals are posnjakite. The pale brown basement is sandstone, host of the deposit.
Recovered from a meteoric oxidation zone of a moderately high-temperature hydrothermal deposit associated with welded tuff. Formed in less than 50 years after the mine was closed,
The first posnjakite from Japan was reported from this location in 1973.