A new method using a combination of Proton Induced X-Ray Emission (PIXE) and diagnostic leaching has been used to characterise the associations and distribution of gold in a variety of ores from the Pilbara region of Western Australia. The different ore types studied highlighted the versatility of the approach and has demonstrated its applicability to any type of ore. Characterisation of an oxide ore deposit has shown how the technique can be used to gain a good initial understanding of potential metallurgical problems for a new ore. From the application of the approach to the study of two other types of refractory ores it was possible to demonstrate that in these ores the gold occurs locked within the sulphide matrix as "invisible gold" and that the form of its occurrence affects its recovery. (c) 2005 Elsevier Ltd. All rights reserved.