We report on a fundamental morphology growth of gold-based nanoparticles by solution radiolysis. Radiolysis of pure gold-polymer solutions of different dose rates and aging time is examined. A detailed description will be presented of the experimentation, testing and analysis. In particular, we will present data on the formation of gold nano-octahedra and -prism particles. The γ-irradiations were carried out with a 60Co source of 1.345 × 105 Ci (Sandia National Laboratories Gamma Irradiation Facility (GIF). Nanoparticle characterization techniques included are UV-vis and TEM. Similar to what has been seen in earlier silver nanoparticle studies, dose rate dictates the size of nanoparticles formed. At high dose rate, all reducing species are produced and scavenged within a short time, and then coalesce into separate nanoparticles. At low dose rate, the coalescence process is faster than the production rate of the reducing radicals. The reduction of radicals occurs mainly on clusters already formed. The differences in the morphologies result from a combination of dose rate, aging and lack of radical scavengers (e.g. isopropyl alcohol), resulting in either gold nano-spheres, octahedral or prism nanoparticles. The progressive evolution with dose rate of the UV-visible absorption spectra of radiation-induced metal clusters is discussed.