Development and application of soft X-ray spectroscopy and cathodoluminescence to minerals

The addition of hyperspectral soft x-ray emission spectrometers (SXES) and cathodoluminescence (CL) spectrometry to electron microprobes gives access to spectroscopies that provide sample information not available from wavelength-dispersive (WDS) or energy-dispersive X-ray spectrometers (EDS). We have developed software and hardware which enables collection of the backscatter electron signal, WDS, EDS, SXES and CL spectral data simultaneously. This unique strategy allows our instrumentation to avoid pixel misalignment and minimises electron beam induced damage artefacts associated with multiple pass mapping. Originally this approach was developed for a JEOL 8530F-CL and most recently has been implemented on a JEOL iHP200F-CL. We have utilised this technology on a range of material and geological problems. Here we show an example of grain orientation information that can be obtained from SXES spectra collected during mapping naturally occurring graphite from a Tanzanian deposit. In addition, a ureilite meteoritic sample, NWA7983, was studied to better understand the formation and presence of lonsdaleite and diamond.