The topic of raw material criticality, exemplified by platinum group metals (comparative to iron,which is being investigated as a potential substitute), opens approaches to sustainable chemistry. In two studentsurveys (N = 295, N = 255), knowledge on this topic was collected. The results show that students have a diffe-rentiated picture of criticality but tend to assume physical scarcity of raw materials and environmental pro-blems as the main causes. The reasons given correspond to everyday ideas about metals.