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

Aluminum prices are expected to remain supported by a supply deficit in 2026, while still subdued alumina prices should continue to support smelting margins, he reckons.

From The Wall Street Journal ● Aug. 10, 2026

Press Metal is still projected to post record annual earnings over the coming years as its alumina plant, due to begin operations in early 2027, improves its cost structure, he adds.

From The Wall Street Journal ● Jul. 28, 2026

Down a country lane on Ireland's west coast, a sign outside Europe's largest alumina refinery greets visitors in English, Irish -- and Russian.

From Barron's ● Jul. 24, 2026

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

It is composed essentially of hydrous silicates of alumina, or more rarely of magnesia.

From Webster's Unabridged Dictionary (2nd 100 Pages) by Noah Webster