Archaeometric analyses of Stone Age pottery are currently being carried out at the NIhK. This involves sherds of the late Ertebølle culture from the Baltic coast of Schleswig-Holstein, which date to around 4600 BC. These finds are among the oldest pottery that we know from Northern Germany. In the course of the investigations within the project Pottery traditions, thin sections of the sherds are prepared. To produce these thin sections, pottery samples are ground down to a thickness of 0.03 mm so that sufficient light can pass through the sample. Using a polarization microscope, the minerals existing in the clay can be identified by their optical properties such as color. Inclusions contained in the clay, such as larger rock fragments, plant material or microfossils, are also clearly visible in the thin sections. In this way, in combination with other investigation methods, including chemical analyses, it is possible to comprehensively characterize the clays used for making pottery. In addition, the investigations provide further insights into the handcraft traditions of that time, which were important for the production of pottery.