Other studies have focused on the activity and influence of the graphitic component using a 14C labelled aurocyanide on highly orientated pyrolytic graphite (HOPG), these studies revealed that Au adsorption predominantly occurred on edge planes (Sibrell and Miller, 1992). Similar studies of aurocyanide adsorption on HOPG in the presence of Ca2+ using novel in situ scanning tunnelling microscopy, was able to atomically resolved clusters of Au that were predominantly found on the graphite basal and edge planes (Poinern and Thurgate, 2003). In addition, other atomically-sized filamentous structures have been located on the HOPG surface in contact with a Au cyanide solution (Poinernet al., 1998).