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 recovery of the manganese. For further purification, the manganese can then be sent to an electrowinning facility. In 1972 the CIA's Project Azorian, through billionaire Howard Hughes, commissioned the ship "Hughes Glomar Explorer" with the cover story of harvesting manganese nodules from the sea floor. That triggered a rush of activity to collect manganese nodules, which was not actually practical. The real mission of "Hughes Glomar Explorer" was to raise a sunken Soviet submarine, the K-129, with the goal of retrieving Soviet code books. Manganese has no satisfactory substitute in its major applications in metallurgy. In minor applications, (e.g., manganese