Only relatively pristine material has the goods Landman is after, so his team USES a scanning electron microscope (below), which utilizes a beam of electrons to image surfaces, to find the best nacre.

Low power scanning electron microscope image of tooth surface, computer-coloured yellow on blue background.

A single pair of beams does not, however, produce a useful image. To do that requires scanning the object beam through the target about a hundred different ways.