The evaporated gold is induced to grow in a (100) orientation. This gives lattice plane spacings of 0.204mm for the (200) planes and 0.143mm for the (220) planes. If the crystal thickness happens to be suitable, and if the objective aperture is large enough to accept the required diffracted beams, a spacing of 0.102mm can be imaged with a suitable focal setting. This specimen thus provides a valuable test for the best microscopes in service.