Dab tsi yog Hliav pob zeb

Hliav zeb zeb yog lub pob zeb siv los hliav riam. Ib qho zeb xuab zeb tuaj yeem hlais tau - qhov av grey clayey sandstone yuav zoo tshaj. Quartz kuj tseem zoo, tab sis nws tsis tshua muaj. Granite tseem muaj. Qhov tseem ceeb yog cov hniav tawg yuav tsum ntse thiab ruaj, tsis raug rau chipping.