a·lu·mi·na
noun/əˈluːmɪnə/
/əˈluːmɪnə/
[uncountable] (specialist)- a white substance found in many types of rock, especially clay
矾土 Word Originlate 18th cent.: from Latin alumen, alumin- related to aluta ‘a kind of leather’, on the pattern of words such as magnesia.