Abstract Illicit trade in gold, mainly sourced from South America and Africa, is used to fund criminal activities such as the drug trade. Laundering money through the purchase of illicit gold, then having it refined and being paid for in clean funds is a major problem, and drives further growth in illicit mining. In order to restrict the influx of illicit gold into the legal domain, it is necessary to be able to identify the traded item as being of a licit or illicit nature. The only way that this can be done with any certainty is by determining, from its chemical composition, the source of the gold and the means by which it has been processed and upgraded. The example dealt with here shows how the use of compositional, processing and geological knowledge is able to discriminate gold from different origins. Data derived from a physical sample is far better able to constrain the source than a paper trail of certification, which can be manipulated.