This study employed Phy-X software to investigate the radiation protection efficacy of different bricks fabricated from a mixture of clay, CaO (calcium oxide), Al2O3 (aluminum oxide), and Fe2O3 (iron oxide). As the oxide additives substituted clay, an increased in the density of the fabricated samples was noticed, with CL5Fe showcasing the superior value of 2.40 g/cm3. An improved linear attenuation coefficient (LAC) was also noticed, with CL5Fe demonstrating the greatest LAC value of 0.154 cm−1 at 0.6 MeV, which could be associated to its superior density due to presence of Fe2O3. The 0.6 MeV energy was chosen as a representative 137Cs value within the Compton-dominant region. Shielding performance was further evaluated from 0.0459 to 1.46 MeV, covering photoelectric-to-Compton-dominated interactions. CL5Fe also outsmarted other samples in terms of thermal stability and structural integrity, making it the best choice for gamma radiation protection. Future studies should evaluate shielding performance across 1.47–15 MeV to assess material suitability for medical imaging, radiotherapy, and nuclear radiation environments.