Manganese is a silvery white, hard, and brittle transition metal. Manganese has a wide variety of industrial alloy uses, particularly associated with the production of stainless steel which accounts for most of the demand. Other leading uses of manganese include construction, machinery, and transportation, as well as aluminum alloys. Manganese improves strength, workability, and resistance to wear. Manganese compounds are used in dry cell batteries, as oxidizing agents, rubber additive, plant fertilizers, in ceramics, glass making, colorant, animal feed and fungicide. Pyrolusite (MnO2) is the most important manganese ore. Pyrolusite occurs under oxidizing conditions in hydrothermal deposits, as well as in bogs often as a result of alteration of manganite, a manganese oxide-hydroxide. Large land-based resources exist but are irregularly distributed. The ocean floor has important manganese resources (manganese nodules), but no economically viable extraction method has been found to date. There is a strong global demand in manganese mostly due to the rising global production of steel. Manganese is on Canada’s 2021 critical minerals list, meaning that it is essential to Canada’s economic security.