500g MANGANESE DIOXIDE

A glaze colorant typically giving browns, blacks and, at high concentrations, metalics. Above 1080º C MnO2 changes to MnO, an active flux; glazes that are molten at 1080º C may show defects due to liberated O2 gas. 1% or less added to a stoneware clay body creates fine, reduction-like specking. The  effect is enhanced if used in combination with granular manganese.