Manganese

What it is and where it is found
Manganese is a silver-white, hard, very brittle transition metal which occurs in nature mainly as brownstone. It is also technically possible to extract manganese nodules from the deep sea. The deposits are almost unlimited. The melting point of manganese is 1,245°C, the boiling point 1,967°C, the density 7.43 g/cm³.

What it is used for
Manganese is used in the form of ferromanganese as an alloying element for steel and/or cast iron. In the process, oxygen and sulphur are extracted, and the steel/iron is hardened at the same time. Tensile strength and yield point are increased, and ductility is improved. Manganese metal is used in alloys with non-ferrous metals, especially copper and aluminum, and increases the strength, corrosion resistance and ductility of the metal. 
As many other metals, manganese in powder form is flammable and reacts with water. Manganese-containing dusts are toxic when they are inhaled.

How it is traded
Manganese is traded in the form of sheets/plates.