Understanding and quantifying the exact composition of mineral samples paves the way towards advanced methodologies that not only increase the effectiveness of ore processing but also enable future recycling technologies. To this end, samples consisting of ground particles embedded into an epoxy matrix are imaged with computed tomography (CT) at micrometer resolution. Due to the sheer amount of particles in each sample, automated image analysis is quintessential to unlocking the potential of his technique. As part of this collaboration we develop a precise and robust instance segmentation method that enables large scale analysis of samples.