Manganese Dioxide MnO2 (coarse)
If your are looking for added speckle in reduced darker clay, add some manganese dioxide: 2 - 10% in both bodies and glazes.
This gives brown colours in glazes, and can produce pink, purple or plum colours in alkaline glazes. When mixed with iron, it produces brown; when mixed with cobalt, it produces violets.
Harmful (Xn). Please read the safety information prior to purchase and use: