The Pedra Preta manganese mine is located in the southwest part of Bahia state. Brazil. The manganese deposits consist of lenticular bodies in which minerais of the alpha Mn0(2) group are dominants. The lens like shaped deposits of manganese ore are intercalated between schists of the Precambrian age. The manganese content of the ores varies from 45 to 53%. The ore is low in silica, alkalis and iron. The Pedra Preta manganese deposit was formed by regional metarnorphism of syngenetic sediments with primary manganese oxides. The ore reserve is almost completely exausted.
