Black powder, soluble in acid, Insoluble in water and nitric acid, nonpoisonous ... Weight: 86.94 Density: 5.026 g/cm3 Appearance: Black powder, soluble in acid, Insoluble in water and nitric acid, nonpoisonous ... glass electronics, magnetic materials, dye, medicine, ceramic, water treatment, etc. Electrolytic Manganese Dioxide