Scanning electron microscopy (SEM) is a technique which enables the observation of solid materials at magnifications of up to X100,000. In addition to producing an image of the sample surface, it is also possible to obtain a chemical analysis (typically qualitative or semi-quantitative) of the material being observed. The method is currently being used for examining a wide range of geological materials (e.g. microfossils, fossil wood, minerals, tephra, sediment pore spaces), but has also been used to study other, non-geological materials (e.g. paint pigments, asbestos, semiconductors, modern plants and insects, archaeological materials).
Most samples can be examined uncoated but in some cases coating may be required (with carbon or gold).
We currently use a Hitachi S3000 SEM with an associated Link Isis energy-dispersive X-ray detection system for chemical analysis.
SEM image of pyrite showing pentagonal dodecahedra faces
X-ray element map of tin ore from Cornwall