(Page 290) Composition of a manganese deposit sample from the Todoroki Mine, Japan

The Todoroki Mine is situated about 25 kilometers to the south-east of Ginzan railway station in Siribesi Province, Hokkaido. The author analysed an interesting specimen of black manganese-ore which had a fractured surface which looked like that of a broken piece of wood. This new manganese mineral was studied in its form, physical properties and chemical composition. The author later named this mineral form as "todorokite".