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 Manganese compounds where manganese is in oxidation state +7, which are mostly restricted to the unstable oxide MnO, compounds of the intensely purple permanganate anion MnO, and a few oxyhalides (MnOF and MnOCl), are powerful oxidizing agents. Compounds with oxidation states +5 (blue) and +6 (green) are strong oxidizing agents and are vulnerable to disproportionation. The most stable oxidation state for manganese is +2, which has a pale pink color, and many manganese(II) compounds are known, such as manganese(II) sulfate (MnSO) and manganese(II) chloride (MnCl). This oxidation state is also seen in the mineral rhodochrosite (manganese(II) carbonate). Manganese(II) most commonly