A white solid that is a major constituent of many rocks, especially clays, and is found crystallized as corundum, sapphire, and other minerals.
Alternative name: aluminium oxide; chemical formula: Al₂O₃
- ‘The silica, alumina, and iron come from sand, clay, and iron ore.’
- ‘The major exports are bauxite, alumina, gold, and diamonds.’
- ‘Already some sites yield little more than a mass of crystallised aluminium oxide.’
- ‘He derived the name from the mineral called alumina, which itself had only been named in English by the chemist Joseph Black in 1790.’
- ‘The metals are dispersed as tiny particles on a supporting framework of porous aluminium oxide.’
Late 18th century from Latin alumen (see alum), on the pattern of words such as magnesia.