How to use X-ray Diffraction to identify mixed materials ?
It is somewhat a trial and error process. You must identify the major peaks and then attempt to match them to known mineral peaks. Once you have a partial match, you then subtract out the peaks and attempt to match the remaining ones. Oftentimes, you will find you have no matches after subtracting out the major peaks, in which case you probably found a mismatch by matching peaks from 2 or more minerals. It helps to have an idea of what minerals you suspect are in the mix to start, to help you make the correct initial match (or even the suspected mineral class). It can be done with 2 or 3 minerals mixed, especially if you know the parent rock type. More than that, forget it! It becomes too complex, especially since the peaks can be additive and mask each other. I have also seen PC programs that will attempt to make this match for you, but they can be trial and error as well.
