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 still known as Hadfield steel (mangalloy). It was used for British military steel helmets and later by the U.S. military. The second largest application for manganese is in aluminium alloys. Aluminium with roughly 1.5% manganese has increased resistance to corrosion through grains that absorb impurities which would lead to galvanic corrosion. The corrosion-resistant aluminium alloys 3004 and 3104 (0.8 to 1.5% manganese) are used for most beverage cans. Before 2000, more than 1.6 million tonnes of those alloys were used; at 1% manganese, this consumed 16,000 tonnes of manganese. Methylcyclopentadienyl manganese tricarbonyl is used as an additive in unleaded gasoline