The electrochemical method of synthesis of gold nanorods in micelles gives substrate solutions that upon spotting and heating on a transmission electron microscope (TEM) substrate result in the nucleation and growth of small gold nanoclusters of narrow size distribution. The size of the nanoclusters, and not their numbers, is found to increased with increasing final temperature to which the substrate is heated. The data are fitted to a mechanism, based on Ostwald ripening in which atomic gold diffusion followed by nucleation on nucleating sites leads to the formation of these small clusters.