Studied are elliptic plates sliced from a columnar black ore mass, collected from the eastern wall of the Tsutsumizawa open pit of the Hanaoka mine in 1960. The plates consist of barite, sphalerite and galena, with small amounts of colloform pyrite and euhedral bipyramidal quartz. Concentric mineral zoning of the plates with finegrained barite rim and porous center with a hole, suggests that the original columnar mass is a chimney from which Kuroko-forming hydrothermal solution vented. Sulfur isotope ratios of sulfide sulfur and sulfate sulfur are consistent with those reported for typical Kuroko deposits. The specimens confirm the occurrence of chimney structure at least at some parts of Kuroko formation, like those observed at the present active venting sites on the sea floor.