Manganese violet - Mn NH4 P2O7
Manganese violet is a remarkable compound. It contains manganese in its +3 oxidation state. The full chemical name is manganese (III) ammonium pyrophosphate. It is a fairly stable compound, which is used as pigment in certain paints. However, with reducing agents in acidic environments, it quickly is dissolved, forming a colorless solution of a manganese (II) salt.