Review of nuclear techniques for process control in the gold and uranium mining industries

Authentication of gold products by nuclear methods

“…Assuming that attempts were made to substitute tungsten for some of the gold in, for instance, a Krugerrand (both gold and tungsten have a specific gravity of 19.3 g/cm 3 ), it could be contemplated to use the difference between the K-absorption edges of the two metals. K, of gold is 80.71 keV, while that of tungsten is 69.51 keV, so that the attenuation of an X-ray beam of energy between these two energies will be fairly sensitive to the presence of tungsten.…”