Raw materials are essential for the global economy and future development depends on their continued supply. Like fossil fuels, minerals are non-renewable. In general, their deposits in the Earth’s crust are also geographically clustered, making security of supply a potential risk. In many cases, the exhaustion of economically competitive minerals deposits in industrialized countries has made supplies increasingly dependent on the political stability of mineral-rich emerging economies. At the same time, increasing demand from these emerging markets, new technologies that require large amounts of rare minerals , low substitutability in applications and low rates of recycling have made economies more vulnerable to potential supply disruptions. Consequently policy-makers in several OECD countries and regions have developed reports that assess the vulnerability of their respective economies to disruptions in the supply of minerals. A common aim of many of these studies is the identification of a list of so-called ‘critical minerals’, defined as minerals for which the risk of disruptions in supply is relatively high and for which supply disruptions will be associated with large economic impacts.