Nyob rau hauv cov txheej txheem ntawm kev tsim cov iav raj, cov khoom siv raw -xws li silica xuab zeb, soda tshauv, thiab limestone- yog thawj zaug sib xyaw ua ke hauv ib qho kev faib ua feem. Tom qab ntawd, qhov sib tov no tau muab tso rau hauv qhov kub siab - qhov cub kub kom dhau los ua melting. Nyob rau hauv kub kub, cov tshuaj lom neeg nyob rau hauv cov ntaub ntawv raw reacts tsim ib tug molten silicate iav kua. Lub molten iav yog ces zoo li tus mus rau hauv daim ntawv ntawm ib tug xeem raj siv tej yam kev molding cov txheej txheem thiab raug rau ib tug annealing txheej txheem los txo cov kev ntxhov siab nyob rau hauv, yog li yielding lub kawg iav xeem raj khoom.
Cov iav kuaj cov raj ua los ntawm silicate iav muaj ntau yam khoom zoo heev, nrog rau cov pob tshab siab, kev ruaj ntseg tshuaj zoo tshaj, thiab muaj zog tiv thaiv tshav kub. Cov yam ntxwv no pab txhawb kev siv dav dav ntawm cov iav kuaj cov raj hauv cov chaw sim thiab cov chaw tshawb fawb tshawb fawb. Piv txwv li, hauv kev sim tshuaj, cov iav kuaj cov raj feem ntau siv los tuav thiab ua rau cov tshuaj reagents; Nyob rau hauv kev tshawb fawb lom, lawv yog siv rau culturing microorganisms los yog hlwb. Tsis tas li ntawd, cov iav kuaj cov raj pom kev siv dav hauv thaj chaw xws li tshuaj, kev tiv thaiv ib puag ncig, thiab kev sim zaub mov.
Cov khoom tseem ceeb ntawm cov iav raj yog silicate iav, uas yog tsim los ntawm melting raw khoom -xws li silica xuab zeb, dej qab zib tshauv, thiab limestone - ntawm qhov kub thiab txias. Cov khoom no tso cai rau cov iav kuaj cov raj nrog cov khoom tshwj xeeb ntawm lub cev thiab tshuaj lom neeg, ua rau lawv ua lub luag haujlwm tseem ceeb hauv ntau thaj chaw.