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

In February, the Chinese automaker FAW announced its initial vehicle integration of a “liquid-solid-state” lithium-rich manganese cell, also claiming 500 Wh/kg.

From The Wall Street Journal • Mar. 28, 2026

The group’s goal is to help the U.S. and allied nations secure sources and supply chains for critical minerals such as lithium, cobalt, nickel, graphite, manganese, uranium and copper.

From The Wall Street Journal • Mar. 16, 2026

The team tested this idea by combining a compound made of manganese, cobalt, and germanium with another made of manganese, cobalt, and arsenic.

From Science Daily • Jan. 12, 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

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