Among the important industrial uses of manganese, according to About.com, is its addition to alloys to improve the hardenability, hardness, stiffness, strength, toughness and wear resistence of steel. When added to steel with antimony and aluminum, it forms ferromagnetic alloys, especially when the alloy includes copper.
Mints use manganese to produce certain coins. According to Reference.com, the United States used the metal in nickels from 1942 to 1954 and began using it in one dollar coins in 2000. In Europe, both 1 and 2 Euro coins contain manganese.
Manganese(IV) oxide is the black material found in the original type of dry cell battery. In newer alkaline batteries, however, the electrolyte responsible for accepting electrons from the zinc is a different chemical.
According to About.com, in the glass industry, manganese dioxide removes the green color caused by iron impurities in the silica. The metal also causes clear glass to take on an amethyst color. It is the mineral impurity responsible for the natural color of the amethyst gemstone.
Condy's crystals, which are potassium permanganate, treat some fish diseases. Scientists also use these crystals as an oxidizing laboratory reagent. Biologists use potassium permanganate solutions as stains and fixatives in preparing biological samples for viewing using the electron microscope.