色・発色
manganese
Japanese: マンガン
A source of purple and reddish-purple color. The purple color intensifies when exposed to high temperatures for a long time (solarization).
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Manganese is a metal oxide that gives glass a purple to amethyst color. It is added in the form of manganese dioxide (MnO₂), and the color ranges from pale purple to deep brownish-purple depending on its concentration. Historically, it has also been used as a decolorizing agent for colorless glass; it is an interesting element that counteracts the blue-green coloration caused by iron.
Manganese may change color or lose its color when fired at high temperatures for extended periods. Additionally, since some glass types are prone to color changes (solarization) caused by UV light, care must be taken regarding the display environment. It also reacts easily with other metal oxides, so care must be taken when combining it with them.
This entry is written in Japanese by Rei Chikaoka and translated for readers outside Japan. If something reads oddly, the original is the source of truth.