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

• alumina vs. aluminum

Example Sentences

See Examples For:

alumina

And it vowed to order an "independent, third-party verification by a competent global company, who will monitor the alumina flows from Aughinish and subsequent export out of Russia".

From Barron's ● Jul. 24, 2026

Production in Ireland was launched in 1983, and the company says it produces around 1.9 million tonnes of alumina a year at the plant.

From Barron's ● Jul. 24, 2026

Alcoa last month also agreed to buy South32’s bauxite, alumina and aluminum operations across Australia, Brazil and South Africa.

From The Wall Street Journal ● Jul. 16, 2026

Alcoa said it and the governments of Australia, Japan and the U.S. have reached a final investment decision to build a gallium production plant at the company’s Wagerup alumina refinery in Western Australia.

From The Wall Street Journal ● Jul. 15, 2026

Half an ounce of the neutral solution of bisulphate of alumina added to 200 gallons of water will precipitate the organic matter therein contained; the water may be then used freely for drinking purposes.

From Health, Happiness, and Longevity Health without medicine: happiness without money: the result, longevity by Louis Philippe McCarty