Which manganese ores are commercially mined?

Commercially exploitable manganese ores are generally defined as those containing greater than 35 percent manganese. The most important ores are primarily oxides, with the carbonate ore rhodochrosite also serving as a significant source.12

The primary manganese ores include:

• Oxide ores: Pyrolusite, romanechite, manganite, and hausmannite. Pyrolusite is considered the chief source of manganese and its compounds.12
• Carbonate ores: Rhodochrosite, which is used for producing ferromanganese alloys.31
• Other minerals: Wad is also noted as an important oxide ore. Additionally, silicate ores such as rhodonite and braunite are frequently found in association with oxide deposits and can contribute to the supply.214

While these terrestrial ores are the primary focus of mining, large quantities of manganese are also found on the ocean floor in the form of polymetallic nodules, which contain lower concentrations of manganese (10 to 20 percent) but are significant for their additional content of cobalt, copper, and nickel.21