Repots on bementite, caryopilite and alleghanyite are very rare in literature of China. Theywere first discovered in the Xiaotianjing manganese deposit in Heqing County, Yunnan Province.On the basis of petrological and mineralogical studies of high-quality manganese deposits aroundthe Yangtze platform and in its neighboring areas, these minerals were successively found in suchareas as Laolong, Dounan and Yuhu of Yunnan, Jiaodingshan of Sichuan, Quijiashan og Shaanxi,Chatun of Guangxi and Bapa of Guizhou. As manganese silicatminerals like bementite are closelyassociated with manganese oxides such as braunite and hausmannite and genetically connectedwith the formation and evolution of manganese minerals, they may serve as indicator minerals ofhigh-quality manganese deposits. Bementite, caryopilite and alleghanyite are as a rule closely associated with each other andresemble each other in appearance. They are brownish red, transparent to semitransparent, assumevitreous or waxy luster, and usually take thin-layered, veinlet and massive form. Theirphysicalproperties are given in Table 1, chemical composition is shown in Table 2, and X-raydare are listed in Tables 3,4 and 5.