Todorokite is a complex hydrous manganese oxide mineral with generic chemical formula 1-x6O12·3-4H2O. It was named in 1934 for the type locality, the Todoroki mine, Hokkaido, Japan. It belongs to the

Manganese nodules, also called polymetallic nodules, are mineral concretions on the sea bottom formed of concentric layers of iron and manganese hydroxides around a core. As nodules can be found in va