Preparing for analytical work
Once your booking is confirmed, the priority is to ensure your samples are ready for analysis—whether you plan to send them to us or work in the lab yourself. To keep your project on schedule and avoid unnecessary delays, please follow the steps below to confirm that your samples meet our preparation standards and that the minerals you wish to analyse are clearly marked and mapped.​
Step 1: Clean polished surface
Ensure your samples have a clean, high-quality polish—see the example on the left for reference. The best way to check the polish on your sample is to used reflected light microscopy, make sure the surface of the sample looks clean and does not contain pervasive scratches. If a sample has been analysed previously, remove any old carbon coating before submission. We will apply a fresh carbon coat in the lab prior to analysis, providing a consistent, known thickness for the most accurate results.
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Image left: A reflected light image of a basaltic shergottite meteorite showing a well polished surface. Oxides are bright phases where silicates are shades of grey.
Step 2: Map out your sample
In order to be efficient while looking for mineral grains to analyse, it is best to clearly map our your samples prior to coming to the lab. The best way to do this is to take reflect light microscopy images of your sample and stitch them together to make a map of the entire sample. You can then clearly mark the grains that you are interested in analysing. This can save a lot of time while on the probe as it can be difficult to find specific grains if you have not mapped out your samples.
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Image right: A reflected light map of a basaltic shergottite meteorite with olivine grains of interest marked in red boxes and labelled.
What your sample will look like under the probe
When your sample is loaded into the probe and you begin the analytical process, you will be observing your sample in backscatter electron (BSE) mode. This produces a greyscale image that is broadly based on the chemistry of the minerals. For example, Fe-rich minerals will appear brighter compared to Mg-rich minerals.
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Image left: A BSE image showing an olivine grain in a pyroxene and plagioclase groundmass containing some bright BSE oxide phases. The red mark indicate where probe spot analyses have been conducted. Note the slightly lighter grey margin of the olivine indicating a more Fe-rich margin.