Using light to describe the ancient world

Handheld x-ray fluorescence spectrometer analysing a fossil antelope horn

X-ray fluorescence (XRF) spectroscopy is a venerable technique that has been applied to countless rocks, but very few fossils. Traditional XRF is destructive, and fossils are precious, but the information provided is incredibly valuable – x-ray fluorescence spectroscopy tells us about the elemental makeup of a sample. X-rays are high energy photons with wavelengths far too short for our eyes to detect. X-rays energise atoms wherever they meet them, boosting the energy of orbiting electrons. The effect is only temporary though, and the bolstered electrons eventually find themselves at unsustainable heights. The electrons shed their newfound energy to return to their original places within the atom. Energy is shed from an electron in the form of an x-ray, and the released x-rays have energies characteristic of the atom they are released from. The goal of XRF spectroscopy (or Energy Dispersive Spectroscopy; EDS) is to collect the x-rays released from atoms, because they can be used to identify the element they have come from.

A new form of XRF spectroscopy has become available very, very recently. Instead of destroying a specimen and analysing it in a lab, samples can be analysed using a handheld device. Looking like pieces from a futuristic arsenal, handheld XRF spectrometers are ideal for describing elemental compositions of fossils because… they are completely non-destructive!

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