The specimen consists of small gold islands on a perforated carbon film, with a light deposition of graphitised carbon. The holes on the film provide information on instrument defects by observation of the over-focused Fresnel fringe.
The graphitised carbon particles (which should be observed where they overlap the holes on the film) give a lattice spacing of 0.34nm. The gold islands provide a coarse measure of particle-to-particle resolution, and some of them will be oriented suitably to give a gold lattice image.