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Alundum

American  
[uh-luhn-duhm] / əˈlʌn dəm /
Trademark.

  1. a brand name for a substance consisting of fused alumina, used chiefly as an abrasive and as a refractory.

Alundum British  
/ əˈlʌndəm /

noun

  1. a hard material composed of fused alumina, used as an abrasive and a refractory

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