Manganese induce a strong green color in glass by forming less-colored iron(III) and slightly pink manganese(II), compensating for the residual color of the iron(III). Larger quantities of manganese are used to produce pink colored glass. Tetravalent manganese is used as an activator in red-emitting phosphors. While many compounds are known which show luminescence the majority is not used in commercial application due to low efficiency or deep red emission. However, several Mn aktivated fluorides were reported as potential red emitting phorshors for warm-white LEDs. But to this day, only KSiF:Mn is commercially available for use in warm-white LEDs. The manganese oxide
Manganese a constituent of natural umber. Manganese(IV) oxide was used in the original type of dry cell battery as an electron acceptor from zinc, and is the blackish material in carbon–zinc type flashlight cells. The manganese dioxide is reduced to the manganese oxide-hydroxide MnO(OH) during discharging, preventing the formation of hydrogen at the anode of the battery. The same material also functions in newer alkaline batteries (usually battery cells), which use the same basic reaction, but a different electrolyte mixture. In 2002, more than 230,000 tons of manganese dioxide was used for this purpose. The metal is occasionally used in coins;