For resolution test of SE and BSE imaging and for chemical mapping in high-resolution systems such as an Auger scanning instrument. Each test specimen has a square grid pattern with large crystals in the center of each square, and very fine crystals at the edges of each grid. Thus, medium and high resolution gap tests are performed on the same specimen. The larger crystals show facets which allow an assessment of the gray level reproduction available at high resolution. Gold particles range from 5 nm to 150 nm approximately.