Volcanic pob zeb Pumice (feem ntau hu ua pumice lossis porous basalt) yog ib hom kev ua haujlwm ntawm kev tiv thaiv ib puag ncig. Nws yog ib qho zoo heev ntxeem tau pob zeb tsim los ntawm iav volcanic, cov pob zeb thiab lwm yam tom qab hluav taws kub tawg. Lub pob zeb volcanic muaj ntau yam ntawm cov zaub mov thiab cov kab kawm, xws li sodium, magnesium, aluminium, silicon, calcium, titanium, manganese, hlau, npib tsib xee, cobalt thiab molybdenum. Nws muaj deb-infrared sib nqus tsis muaj hluav taws xob tawg, Tom qab ntau txhiab xyoo, tib neeg tib neeg tau pom nws tus nqi ntau dua thiab ntau dua. Tam sim no nws tau txuas rau thaj teb ntawm kev tsim kho, kev txuag dej, kev sib tsoo, cov ntaub ntawv lim dej, cov nqaij ci ci hluav taws, kev tsim kho vaj zaub, kev cog qoob loo, cog cov khoom lag luam zoo nkauj thiab lwm yam. Nws yog lub luag haujlwm tsis paub hauv lub neej txhua qhov! Pob zeb kub ci rov qab yog ib hom kev kho pob zeb, uas siv cov pob zeb ua hluav taws kub kom nqus tau lub zog tsis zoo ntawm tib neeg lub cev, pab tib neeg lub cev tshem tawm cov co toxins thiab txhawb tib neeg cov metabolism.