An X‐Ray Diffraction Study of Manganese Dioxide

An x‐ray diffraction study has been made of the various types of manganese dioxide with particular emphasis on those prepared chemically. A review of the literature suggests that several types have received different names by different investigators. A diffraction pattern of ramsdellite, uncontaminated by the lines of pyrolusite, is reported. Three modifications of are described and their relation to ramsdellite and pyrolusite is discussed. The manner in which lead is combined in a commercial manganese dioxide by‐product, and the part played by potassium in determining the course of various transformations, are also discussed.