Seminar paper from the year 2013 in the subject Geography / Earth Science - Miscellaneous, grade: 1,7, RWTH Aachen University (Lehr- und Forschungsgebiet Geologie - Endogene Dynamik), course: Structural Geology: Microstructural Analysis, language: English, abstract: The Subgrain Size Piezometric is done by a Triassic halite from the upper bunter formation in Hengelo, Netherlands. The rock salt halite is white and normally in thin sections are no crystal boundaries observable, because of the cubic crystal structure and its optical isotropy. To make even the sub grain boundaries visible, the sample has to prepared in a special way, where the crystals appear blue and the boundaries white. For the Subgrain Size Piezometric we uploaded first a picture 430.9-1, which we took as an example, in the program ImageJ and changed the type to 8-bit. The next step is adjusting the threshold. The program allows an automatically threshold, but for a better analysis it does be done manually. Figure 1 shows the converted image. Other programs for example MATLAB or ArcGIS can be used as well. [.]