A process is for extracting natural hydroxyapatite from bone in order to make granules for a bone graft. The process involves soaking and boiling raw bone cubes in deionized water. Soaking and boiling removes lipids, blood components, and proteins and creates bone cubes. Next, washing the bone cubes in deionized water and drying the bone cubes. Then, segregating cancellous bone cubes with densified porous structure from those without densified porous structure. After that, soaking the cancellous bone cubes with densified porous structure in a solution of sodium hydroxide and a solution of hydrogen peroxide. Next, washing the cancellous bone cubes with densified porous structure in deionized water and drying the bone cubes. Then, sintering the cancellous bone cubes with densified porous structure. After that, fracturing the cancellous bone cubes with densified porous structure into the granules for the bone graft.