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 government is investing $150 million for an equity stake in Atlantic Alumina to support what the company envisions as a $450 million expansion and gallium project.

From The Wall Street Journal • Feb. 9, 2026

The aluminum manufacturer is buying Alumina Limited in an all-stock deal valued at about $2.2 billion.

From Seattle Times • Feb. 26, 2024

Rio also said on Friday it was reviewing Rusal’s 20 percent stake in the Queensland Alumina refinery.

From Reuters • Apr. 17, 2018

On Monday, aluminum firm Sherwin Alumina filed for chapter 11 bankruptcy.

From Washington Post • Jan. 11, 2016

The clay which is best for brick-making, contains Silica, and Alumina in about the following proportions: Silica ...

From Draining for Profit, and Draining for Health by Waring, George E. (George Edwin)