alumina

American  

[uh-loo-muh-nuh] / əˈlu mə nə /

noun

1. the natural or synthetic oxide of aluminum, Al 2 O 3 , occurring in nature in a pure crystal form as corundum.

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alumina British  

/ əˈluːmɪnə /

noun

1. another name for aluminium oxide

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alumina Scientific  

/ ə-lo̅o̅′mə-nə /

1. Any of several forms of aluminum oxide used in aluminum production and in abrasives, refractories, ceramics, and electrical insulation. Alumina occurs naturally as the mineral corundum and, with minor traces of chromium and cobalt, as the minerals ruby and sapphire, respectively. In its hydrated form it also occurs as the rock bauxite. Also called aluminum oxide. Chemical formula: Al ₂ O ₃ .

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Etymology

Origin of alumina

1780–90; < Latin alūmin-, stem of alūmen alum ¹ + -a ⁴

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Compare meaning

How does alumina compare to similar and commonly confused words? Explore the most common comparisons:

• alumina vs. aluminum

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Example Sentences

See Examples For:

alumina

The company also held its full-year projections for alumina production and shipments of 9.5 million to 9.6 million metric tons and 11.5 million to 11.6 million metric tons, respectively.

From The Wall Street Journal ● Oct. 15, 2026

Alunorte is one of the world’s largest alumina refineries outside of China and has a capacity of 6.3 million metric tons a year, according to Norsk Hydro.

From The Wall Street Journal ● Oct. 6, 2026

The company’s vertically integrated supply chain provides stable, low-cost bauxite and alumina feedstock, which could enable it to maximize earnings from rising aluminum prices, say the analysts.

From The Wall Street Journal ● Aug. 25, 2026

The investigation was however unable to determine where alumina was traded once it entered Russia because of a lack of internal Russian trade data, he added.

From Barron's ● Jul. 24, 2026

Scapolite, skap′ō-līt, n. a silicate of alumina and lime, occurring in long rod-like crystals.

From Chambers's Twentieth Century Dictionary (part 4 of 4: S-Z and supplements) by Various

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