Article: Scanning electron microscopy of uncoated fossils

The necessity of coating fossils with a conductor prior to scanning electron microscopy is avoided using a system in which backscattered electron images are formed of specimens maintained under a relatively low vacuum in an 'environmental chamber'. Resolution and other image characteristics at low magnifications ( < 500 x) generally compare favourably with conventional secondary electron images of coated specimens. Charging artefacts are reduced, edge effect is eliminated, and the backscattered electron image appears flatter than a conventional secondary electron image. As well as minimizing sample preparation time, the system is valuable in allowing scanning of fossils for which coating is either undesirable (e.g. type specimens) or difficult (e.g. large specimens).