The evolution of the aggregation of condensed matter from single atoms to three-dimensional structures represents an important topic in nanoscience, since it contains essential information to achieve tailor- made growth of nanostructured materials. Such an issue is particularly important in the case of the formation of nano-oxides, which have strong potentialities in heterogeneous catalysis reactions. Herein, we show that a low-nuclearity graphene supported Ag cluster (formed by 11 atoms) shows a local AgO4 configuration, spatial charge distribution and two oxidation states that are similar to those of bulk AgO. This result indicates that bulk oxide conformations can start to develop already for extremely small atomic aggregates (