This study presents a comprehensive 4E analysis of a conical solar still (CSS) integrated with black granite as a novel, low-cost sensible heat storage (SHS) medium. Three configurations were experimentally examined: a traditional conical solar still (TCSS) and two modified versions integrating 2 kg (MCSS-2BG) and 4 kg (MCSS4BG) of black granite distributed over the absorber surface. The thermophysical characterization of the granite, supported by SEM and EDS analyses, confirmed its suitability for solar thermal applications due to its strong absorptivity and stable mineral structure. Experimental results demonstrated significant thermal enhancement, with the modified stills achieving basin water temperatures up to 68 degrees C and extended evaporation periods. The MCSS-2BG and MCSS-4BG configurations increased daily freshwater yield to 6.7 L/m2 and 7.7 L/m2, respectively, representing 39.6% and 60.4% improvements over the TCSS. Energy efficiencies rose from 47.12% (TCSS) to 65.61% and 78.15%, while exergy efficiencies increased from 0.185% to 0.312% and 0.426%. The economic assessment showed a reduction in payback time from 46 days (TCSS) to 34 and 31 days for the modified designs, accompanied by a 25-33% decrease in cost per liter. Overall, under the tested conditions, the findings demonstrate that black granite is a highly effective and economically viable thermal enhancement material, with strong potential to improve the performance of conical solar stills in arid environments.