METHODS AND CHALLENGES OF ESTABLISHING THE GEOGRAPHIC ORIGIN OF DIAMONDS

There is growing interest in developing methods to deduce the geographic origin of diamonds. Most approaches have focused on trace elements within diamonds, which can be sensitive recorders of geological conditions during the growth of minerals. Gem-quality diamonds have ultra-low concentrations of trace elements, making them extremely challenging to analyze quantitatively. Nonetheless, high-quality trace element data from multiple studies reveal complex and variable patterns, but with striking similarities and overlap between worldwide deposits. Diamond properties such as trace element or isotopic characteristics vary as a function of geological conditions that are not necessarily distinct and resolvable between diamonds of different geographic origin. We conclude that there has been no study by any method demonstrating unique and measurable characteristics that would allow for independent provenance determination of a random individual diamond. For now and the foreseeable future, the only definitive method to establish diamond origin depends on preserving and retaining origin information from the time of mining.