Ukwakheka kwamakhemikhali kobuhlalu obuntantayo ikakhulukazi yi-silicon dioxide ne-aluminium oxide. Kunezici eziningi ezifana nezinhlayiya ezincane, okungenalutho, isisindo esincane, amandla aphezulu, ukumelana nokuguguleka, ukumelana nokushisa okuphezulu, ukuvikela ukushisa kanye nokuvimbela ilangabi. Kusetshenziswa kabanzi kwenye yezinto zokusetshenziswa embonini yokungaguquki.