<Original Papers>Mineral Composition of Oxide Ore from Maruyama Mine, Hokkaido, with Special Reference to Hetaerolite and Coronadite

The ore deposits of Maruyama mine are epithermal zinc-lead-manganese veins cutting Palaeozoic formation, consisting mainly of slate with some intercalations of sandstone and chert. The upper part of the deposits has been oxidized by supergen solutions. Coronadite, nsutite, birnessite, todorokite, chalcophanite, hetaerolite, hydrohetaerolite, goethite, cerussite, smithonite, rhodochrosite, sphalerite and quartz were detected in the microscopic, X-ray and electron microprobe studies of materials from oxidation zone. This is the second occurrence of coronadite, hetaerolite and hydrohetaerolite reported in Japan. The chemical analyses of coronadite, hetaerolite and hydrohetaerolite the following empirical formulas : coronadite, Pb_ (Mn^_ Zn_ Mn^_ Fe^_ Si_)_ O_ ; hetaerolite, (Zn_ Pb_)_ (Mn^_ Si_)_ O_ ; hydrohetaerolite, (Zn_ Pb_)_ (Mn^_ Fe^_ Si_)_ O_. 0.55H_2O