Glendonite
Tateya, Akiruno city, Tokyo metropolis, Japan
Length of upper right crystal: 20 mm. Dispatched specimens of glendonite. The upper-right specimen is short prismatic, whereas the upper-left one has clear pyramidal planes. There are also specimens which looks like a twin.
Recovered from marine mudsone. Formed in Miocene (19 Ma).
Glendonite from this location was described in 1977.