Cov tshuaj muaj pes tsawg leeg ntawm cov hlaws ntab yog feem ntau silicon dioxide thiab aluminium oxide.Nws muaj ntau yam zoo xws li cov khoom zoo, hollow, lub teeb yuag, siab zog, hnav tsis kam, kub tsis kam, thermal rwb thaiv tsev thiab nplaim retardant.Nws yog dav siv nyob rau hauv Ib qho ntawm cov khoom siv raw rau kev lag luam refractory.