Manganese Dioxide

Manganese Dioxide, MnO₂, can be found as the black or dark grey mineral pyrolusite.
Common industrial applications of manganese dioxide include: dry cell battery material, pigments, and chemical intermediate or reagent. Manganese can be used as a precursor chemical in the preparation of MnO (manganous oxide) and KMnO₄ (potassium permanganate).

Ceramic :
Above 1080°C (1976°F), MnO₂ will expel oxygen and become MnO, which may then work with the surrounding silica to produce violet and or brown colors (if reacting also with alumina).
Other colors that manganese dioxide can produce include: purple, soft brown, black, and red.

Additional Notes:
* Manganese glazes expel oxygen at temperatures over 1080°C (1976°F) and may blister or ruin the final result. The fumes during firing are highly toxic!
* The heated oxidation (O₂) of 2MnO₂ and 4KOH produces 2KMnO₄(a green crystal) and 2H₂O. This potassium manganate may be used to produce potassium permanganate, a useful purple-colored material useful as a potent fire accelerator and water purifier.