For long time, the main ore type in Mittersill was the K1-gneiss. Nowadays the orebodies in the footwall are mined. They consisting amphibolites and schists with a higher content of micas, talc and chlorite. These minerals causes problems in the processing plant. This work should classify the content of minerals of the mined orebodies and the ocurrence of fault zones. The fault zone can reach 2 meters in size and consists only talc, chlorite and minor quartz. This causes a very inhomogeneous ore. The processing plant would need a homogeneous ore to work with right setup of the mill. Therefore, a analysing-method with XRD was developed. Samples with different talc-contents were made, to create a calibration curve for the XRD. This method should allow a forecast of the contents of all minerals.