The Influence of Manganese Oxide on some Properties of Glass
JSGT_1931_V15_T172_T184
There are two important purposes for which manganese oxide is employed as a constituent of glass, the first being as a decoloriser, for which a very small proportion suffices, the second for producing a variety of colourings, in which case, as, for example, in bottle glasses, it may be present in amounts up to 3 or 4 per cent.
A. A. Childs, Violet Dimbleby, F. Winks & W. E. S. Turner