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

Then, at around ~720 mV, a manganese based layer forms on top of the chromium based layer.

From Science Daily • May 10, 2026

The agreement aims to give Europe better access to these materials, most notably aluminium, lithium and manganese.

From Barron's • Apr. 23, 2026

It has retained its majority shareholding in South African miner Kumba Iron Ore, as well as an interest in a local manganese business and its sprawling wine farm, Vergelegen, outside of Cape Town.

From The Wall Street Journal • Feb. 6, 2026

Brazil is one of the world’s major sources of the world’s iron ore, and has vast—yet underdeveloped—deposits of rare earths such as manganese, Lifton said.

From Barron's • Jan. 9, 2026

A poor pharmacist with little in the way of advanced apparatus, he discovered eight elements–chlorine, fluorine, manganese, barium, molybdenum, tungsten, nitrogen, and oxygen–and got credit for none of them.

From "A Short History of Nearly Everything" by Bill Bryson