manganese

American  

[mang-guh-nees, -neez] / ˈmæŋ gəˌnis, -ˌniz /

noun

Chemistry.

1. a hard, brittle, grayish-white, metallic element, an oxide of which, MnO 2 manganese dioxide, is a valuable oxidizing agent: used chiefly as an alloying agent in steel to give it toughness. Mn; 54.938; 25; 7.2 at 20°C.

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manganese British  

/ ˈmæŋɡəˌniːz /

noun

1. a brittle greyish-white metallic element that exists in four allotropic forms, occurring principally in pyrolusite and rhodonite: used in making steel and ferromagnetic alloys. Symbol: Mn; atomic no: 25; atomic wt: 54.93805; valency: 1, 2, 3, 4, 6, or 7; relative density: 7.21–7.44; melting pt: 1246±3°C; boiling pt: 2062°C

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manganese Scientific  

/ măng′gə-nēz′ /

1. A grayish-white, hard, brittle metallic element that occurs in several different minerals and in nodules on the ocean floor. It is used to increase the hardness and strength of steel and other important alloys. Atomic number 25; atomic weight 54.9380; melting point 1,244°C; boiling point 1,962°C; specific gravity 7.21 to 7.44; valence 1, 2, 3, 4, 6, 7.

2. See Periodic Table

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Etymology

Origin of manganese

1670–80; < French manganèse < Italian manganese, alteration of Medieval Latin magnesia magnesia

Example Sentences

See Examples For:

manganese

More than 70 percent of its population of 22 million lives on less than $3 a day, according to the World Bank, despite the country also having significant potential in cobalt, nickel and manganese.

From Barron's ● Aug. 16, 2026

Despite also having significant potential in cobalt, nickel and manganese, the country continues to struggle with persistent poverty, unemployment and rising food prices.

From Barron's ● Aug. 14, 2026

What makes the result especially striking is the role played by manganese.

From Science Daily ● Aug. 11, 2026

It views South32’s 3Q results as “a mixed set,” highlighting misses in copper, zinc and manganese production offset by better-than-expected aluminum output.

From The Wall Street Journal ● Apr. 22, 2026

They were cobalt blue, purple from manganese, yellow from copper, red, and a green which was also got from copper.

From "The Once and Future King" by T. H. White