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

The alumina industry’s reliance on the Strait of Hormuz, through which maritime traffic was mostly blocked during much of the first quarter, put pressure on alumina prices and demand, Chief Executive Bill Oplinger said.

From The Wall Street Journal • Apr. 17, 2026

Alcoa affirmed its full-year outlook for production and shipments of both alumina and aluminum.

From The Wall Street Journal • Apr. 16, 2026

Alcoa ships some alumina to the Middle East.

From Barron's • Mar. 30, 2026

Morgan analyst William Peterson wrote in a recent note to clients that roughly a third of Alcoa’s alumina capacity is contracted to “key players” in the Middle East, including EGA and Alba.

From MarketWatch • Mar. 30, 2026

Pure alumina or calcined Aluminium is a chemical product.Ammonia.—A volatile gaseous matter, found in some clays.

From Pottery, for Artists Craftsmen & Teachers by Cox, George J.