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

Compare meaning

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

• alumina vs. aluminum

Example Sentences

See Examples For:

alumina

Stephenson said ministers should work with the EU to secure alternative markets for the refinery's alumina while preparing contingency plans, including examining nationalisation if necessary.

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 cut its full-year alumina guidance, citing issues at its alumina refinery in Pinjarra, Australia, and reported a higher second-quarter profit.

From The Wall Street Journal ● Jul. 16, 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

Some portions of glass of this character have been analyzed by me, when I found that these white spots were owing to the presence of a glass containing alumina.

From British Manufacturing Industries Pottery, Glass and Silicates, Furniture and Woodwork. by Arnoux, L.