Book excerpt: Metallic Mineral Resources: The Critical Components for a Sustainable Earth serves the increasing interest in metal resources, especially the critical and strategic metals which are essential commodities for the green energy transition. The opening chapters introduce the heterogeneous distribution of metal resources as well as the industrial use of metals. The main chapters then work systematically through abundant metal systems, scarce critical metal systems, rare critical metal systems, trace critical metal systems, and precious metal systems. The book wraps with a close examination of temporal distribution of mineral resources and an insightful discussion of the future of mineral resources. Researchers and engineers in economic geology and mining and exploration industries will find themselves returning to this key reference for years to come.• Describes how mineable and economic metal concentrations form and are preserved in the Earth's upper crust • Explores how they are discovered by systematic mineral exploration at a variety of scales • Discusses how to educate the public on the scarcity of natural metal resources and the issues concerning the nexus between the energy transition and potential exhaustion of critical metals