Advanced Spectroscopic Techniques for Separating Natural and Synthetic Diamond Gemstones

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Knowing the origin or provenance of a diamond gemstone with certainty is critical to determining its value. This question goes deeper than whether the diamond is of synthetic or natural origin. Information about a gemstone's provenance is increasingly important in reassuring the consumer that their diamond has been ethically sourced and that best practice has been maintained throughout its production.Synthetic gemstone-quality diamond material can now be produced by high pressure high temperature (HPHT) or chemical vapor deposition (CVD) growth methods. However, since natural untreated diamonds are valued above treated diamonds or synthetics, customers need to be convinced that undisclosed synthetics can be detected with a high degree of confidence. One ofthe most powerful analytical weapons in the gemmologist's armoury is optical spectroscopy because it can record the optical characteristics of a gemstone in a quantifiable and reproducible way. The technique is also inherently non-destructive. Certain optical signatures will raise suspicion by indicating the presence of additional elements, or point and extended defects, not commonly found in natural diamonds. Likewise, certain optical signatures can reveal clues about the growth conditions when the crystal was forming, conditions that will be significantly different for natural and synthetic diamonds. As the quality of synthetic diamond gemstones continues to improve, it is increasingly important to develop more advanced spectroscopic interrogation techniques to keep ahead. This project will be supervised by Dr Georgina Klemencic (Cardiff), Dr Stephen Lynch (Cardiff) and Dr Colin McGuinness (De Beers). Cardiff University and De Beers have previously worked closely together to understand unusual spectral signatures that were found in synthetic gemstones. This project will build on the legacy of this work. We are seeking a student to continue to develop a spectroscopic imaging experiment able to explore the luminescence behaviour of diamond under pulsed ultraviolet illumination over a range of timescales and temperatures. It is expected that the student will spend up to 6 weeks per year at De Beers research laboratories in Maidenhead validating their work. This PhD project thus provides an exciting opportunity to perform cutting-edge physics research that is also industrially relevant. While working at De Beers, the student will receive unique bespoke training and they will be able to experience the research and development environment in a multinational company.