ABSTRACT
This chapter examines the primary concepts involved in mineral resources, mining and supply, examines the factors used to assess criticality, and discusses the wide variety of complex and often inter-related factors which affect the criticality of numerous metals which are increasingly in demand in the modern world. It discusses the resource nexus – the relationships between metals supply and other environmental, social and economic factors which will underpin our ongoing ability to meet potential supply scenarios for numerous technology metals. In essence, to make a metal worth extracting from the earth's crust there needs to a sizeable body of enriched rock – that are, rich concentrations in rock from which the metals of interest can be extracted, with typical enrichment factors ranging from tens to thousands of times crustal abundance. Overall, there is a strong growth trajectory expected for rare earth elements to meet the demands of an increasingly affluent global population and its increasingly complex technological mix.
