corundum

noun/kəˈrʌndəm/

Frequency rank: #19,779 most common English word

Meaning

A very hard mineral (aluminum oxide) that forms gems such as rubies and sapphires.

Illustration for the English word “corundum”

Example sentence

The gemologist explained that rubies and sapphires are both varieties of corundum.

Synonyms & related words

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