alumina

views updated May 29 2018

alumina (aluminium oxide, Al2O3) Mineral used as an abrasive, electrical insulator and furnace lining. Other forms of alumina include corundum, two impure varieties of which are the gemstones sapphire and ruby.

alumina

views updated May 17 2018

a·lu·mi·na / əˈloōmənə/ • n. aluminum oxide, Al2O3, a white solid that is a major constituent of many rocks, esp. clays, and is found crystallized as corundum, sapphire, and other minerals.

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