Outline and Problems of Studies on the Manganese Dioxide Minerals from Japan

Naturally occurring seventeen manganese dioxide minerals, cryptomelane (ishiganeite), hollandite, manjiroite, cororadite, pyrolusite , nsutite (yokosukaite), ramsdellite, birnessite, rancieite, takanelite, todorokite, lithiophorite, psilomelane, chalcophanite, hydrohetaerolite, auroite and amorphous manganese dioxide mineral , from Japan were briefly reviewed from the stantpoints of descriptive mineralogy, together with the relation between the terrestrial manganese dioxide minerals and the composition of manganese nodules.