Heterogeneous Example: Gold-Plated Tungsten Alloy
The base metals are clearly visible in this sample. The detector “sees” roughly equal parts of gold and tungsten from the Xrays that are absorbed on the gold surface and base metal interior, respectively.
A separate point of interest: Note that the apparent composition delivered by the quantitation software of ~36% gold is probably inaccurate due to overlap of the W Lb line, which is being used in the default quantitation method, with the Au La line. An empirical or custom method would be better suited for an application involving a combination of gold and tungsten.