Mining and supply of black manganese in Brazil  is more and more popular.Many investors want to invest the Mining  of black manganese in Brazil. Hausmannite tetragonal system, the crystal was a square bipyramid, usually as granular aggregates. The color is black, streak brownish orange or reddish brown. The semi-metallic luster. Hardness 5.5, specific gravity 4.84. Hausmannite is formed by the

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