A pegmatite shaped like a vertical pipe of 60m diameter. Worked for its major components (perthitic feldspar and quartz) for the ceramic industry. Unusually rich in yttrium-bearing minerals.
The largest pegmatite body in an area rich in other pegmatites.
Mining started in 1916 and closed in the early 1980s.
According to Hori et al. (2006) Iizaka (Iisaka) Village is the old locality name; the pegmatite is near Kawamata town.
Refs.:
Hasegawa (1957), Sci. Rept. Tohoku University, Third series: 5: 345-371.
Hori, H., Kobayashi, T., Miyawaki, R., Matsubara, S., Yokoyama, K., Shimizu, M. (2006): Iwashiroite-(Y), YTaO4, a new mineral from Suishoyama, Kawamata Town, Fukushima Prefecture, Japan. Journal of Mineralogical and Petrological Sciences, 101, 170-177.
Hoshino, M., Kimata, M., Shimizu, M., Nishida, N., and Fujiwara, T. (2006) Allanite-(Ce) in granitic rocks from Japan: Genetic implications of patterns of REE and Mn enrichment. Canadian Mineralogist: 44: 45-62.