Surfactant stabilized gold clusters have been deposited on graphite and studied with scanning tunneling microscopy in vacuum. Cluster layers with a superlattice constant of≈31 Åwere found, extending over several micrometers. The clusters form a hexagonal lattice which is ordered over distances of about 100 Å. At low sample biases(<0.75 V)the clusters are not imaged, consistent with a Coulomb blockade effect. ©1997 American Institute of Physics.