Results have shown that (Granite) is one of the best building materials to be used in shielding against gamma rays, whereas the (Thermostone) showed less 75 ﺇﺴﺭﺍﺀ ﻤﺤﻤﺩ ﺤﺴﻥ ﻭ ﻟﻴﺙ ﺃﺤﻤﺩ ﻨﺠﻡ 76 ability to attenuation because of its too low density and the little concentration of ...Web