Using Live Chemical Imaging to Understand a New Geological Sample

I was recently given a geological sample to look at by a colleague. It hadn’t been looked at for a long time, and we didn’t really have any information on it. From looking at the sample with the naked eye, it was clear that it was a geological sample – a granite containing a number of different phases (prior to working for Oxford Instruments, I was a geologist). However, I wanted to know significantly more about it – specifically what the phases were that made it up and whether certain phases of interest are present within it.

Historically, in order to get an understanding of this sample, I would start off by looking around the sample on the SEM, imaging it using a backscattered electron detector. By doing this, I would have an image that gave an indication of compositional variations to navigate with in order to try and find interesting parts of the sample. If I found something that looked like it might be interesting, I would stop and collect either an EDS point spectrum or map to decide if it actually was of interest and then, if it wasn’t, move on, repeating the process until I found what I was after.

This, of course, was a rather time-consuming approach which could also be both laborious and, at times, frustrating. This was due to a number of things. Firstly, in samples like this one, many of the phases of interest are often of quite similar mean atomic number– meaning that they are hard to tell apart from each other in a BSE image – and so the process of differentiating minerals via BSE is hampered. Secondly, finding areas of particular interest took a long time, as it was essentially a case of making an educated guess on where to stop and investigate.

So, back to me wanting to understand that sample that was given to me… Thankfully, nowadays we have a far more efficient approach than the one that I described above which gives us all the information we need at once – even when we’re moving around our sample: Live Chemical Imaging in AZtecLive.

In the video below, you can see what happened when I looked at this sample with Live Chemical Imaging in AZtec 6.0.  You can see how, almost straight away, I was gathering useful information that informed my understanding of this unknown sample. I was also able to find a phase of particular interest in the sample and very quickly work out to what extent it was present.

I think that it’s quite clear from the video just what a difference Live Chemical Imaging has made to the process of trying to understand an unknown sample when it first goes into the microscope. I learnt a huge amount about the sample in a very short amount of time with very little effort. It really is true to say that this approach has completely altered (and improved!) my approach to starting off my analyses.

If you’d like to learn more about how Live Chemical Imaging can revolutionise your analysis and see it being used, then I’d urge you to watch our webinar: “Revolutionise Your SEM Capabilities with Live Chemical Imaging” which you can access via our webinar page.

Dr Matt Hiscock

Head of Product Science and Solutions