Procedures are described for the evaluation and isolation of trace mineral particles from sample populations at the ppm level by dual energy rapid scan radiography using an X-ray microtomography instrument (XMT). After calibration of the XMT, the samples are split into narrow size fractions, each size fraction distributed/assembled on projection plates, and then the plates placed in the sample holder of the XMT for irradiation at two energy levels (dual energy analysis). In this way, for example, more than 200,000 particles of 250 x 150 mu m in size can be interrogated in less than 1 h and the composition of particles containing high density mineral phases estimated. These trace particles can be isolated for 3D analysis by high resolution X-ray microtomography and/or selected for surface characterization using XPS, TOF/SIMS, or other analytical instruments. Rapid scan radiography can be used for the examination of drill core samples, tailings samples, or any other particulate sample containing trace mineral particles. (C) 2012 Elsevier Ltd. All rights reserved.