Mineragraphic Identification Of Psilo-Melane And Manganite¹

In the course of some recent mineragraphic work on the man-ganiferous iron ores of the Cuyuna Range, Minnesota, undertaken by the Mississippi Valley Experiment Station of the United States Bureau of Mines in cooperation with the Missouri School of Mines and Metallurgy, Rolla, Missouri, it was necessary to make quick identification of the various oxides of iron and manganese. Hematite and psilomelane were found to be the predominating minerals, although the occurrence of manganite and pyrolusite was important to the problem in hand. The mineragraphic characteristics of these four minerals are shown in Table 1.