R1: Characterization and description of minerals (Joint Session with The Gemmological Society of Japan)

[R1P-06] Arsenic-bearing minerals (arsenic, zýkaite) from Tozawa, Gunma Prefecture

*Takashi Yamada¹, Yasuhiro Kosuge², Takashi Fujiwara³, Takashi Ishibashi³ (1. Friends of Mineral, Tokyo/Masutomi Museum of Geo-science, 2. Friends of Mineral, Tokyo, 3. Masutomi Museum of Geo-science)

Keywords:Tozawa, arsenic, zýkaite, kaňkite

During investigating minerals from the old gold mine at Tozawa, Gunma Prefecture, we found arsenic and arsenopyrite in quartz vein with gold, stibnite, pyrite, realger. Also, arsenolite, kaňkite, zýkaite, pitticite, gypsum are found as secondary minerals. Zýkaite occurs as white earthy nodules composed of fine needles. Fe, As, S and O are detected by qualitative chemical analysis. X-ray powder diffraction profile shows good agreement with that of ICDD 29-695.