X-ray diffraction and selective chemical extraction methods were used toinvestigate the types of manganese mineras in iron-manganese
nodules of several soilsin China. The changes of relahve intensity of
X-ray diffraction patterns were studiedbefore and aftor chemically selective extraction. It was found that lithiophorite was acommon manganese mineral in all tested iron-manganese nodules with high degree ofcrystallinity. Tedorokite, however, was predominant manganese wineral of iron-manganese nodules in cal-aquic Vertisols of Shandong province (No. 5-4). Theironmanganese nodules of aorudic Luvisols (No. 2-1, No. 4-1) in Hubei provincecontained birnessite and vemadite. Moreover, hollandite was found in iroruanganesenodules of alt-udic Ferrisols in Yizhang, Hunan province (No.A), arp-udic Luvisols(No.4-1) in Zaoyang, Hubei province and cal-aqulc Venisols (No.5-1) in Shangdongprovince. There were a few of coronadite in ironrmanganese nodules of alt-udicFenisol in Guiyang, Hunan province (No- 1-1). The types and amounts of manganesendnerals in soil ironrmanganese nodules were related to conditions of soil materialsand environments.