As the importance and dependence of specific mineral commodities increase, so does concern about their supply. The United States is currently 100 percent reliant on foreign sources for 20 mineral commodities and imports the majority of its supply of more than 50 mineral commodities. Mineral commodities that have important uses and face potential supply disruption are critical to American economic and national security. However, a mineral commodity's importance and the nature of its supply chain can change with time; a mineral commodity that may not have been considered critical 25 years ago may be critical today, and one considered critical today may not be so in the future. The U.S. Geological Survey has produced this volume to describe a select group of mineral commodities currently critical to our economy and security. For each mineral commodity covered, the authors provide a comprehensive look at (1) the commodity's use; (2) the geology and global distribution of the mineral deposit types that account for the present and possible future supply of the commodity; (3) the current status of production, reserves, and resources in the United States and globally; and (4) environmental considerations related to the commodity's production from different types of mineral deposits. The volume describes U.S. critical mineral resources in a global context, for no country can be self-sufficient for all its mineral commodity needs, and the United States will always rely on global mineral commodity supply chains. This volume provides the scientific understanding of critical mineral resources required for informed decisionmaking by those responsible for ensuring that the United States has a secure and sustainable supply of mineral commodities.

This comprehensive resource is published on an annual basis, and is considered the earliest Government publication to furnish estimates covering nonfuel mineral industry data for the United States and worldwide. Each chapter of this 2015 edition includes information on events, trends, and issues for each mineral commodity as well as discussions and tabular presentations, including data sheets on domestic industry structure, Government programs, tariffs, 5-year salient statistics, and world production and resources for more than 90 minerals and materials. The Mineral Commodity Summaries (MCS) is the earliest comprehensive source of 2014 mineral production data for the world. More than 90 individual minerals and materials are covered by two-page synopses. For mineral commodities for which there is a Government stockpile, detailed information concerning the stockpile status is also included in the two-page synopsis. Abbreviations and units of measure, and definitions of selected terms used in the report, are in Appendix A and Appendix B, respectively. "Appendix C--Reserves and Resources" includes "Part A--Resource/Reserve Classification for Minerals" and "Part B--Sources of Reserves Data." A directory of USGS minerals information country specialists and their responsibilities is Appendix D. Numerous charts and tables representing United States domestic and worldwide resources are contained within this volume for each mineral to provide a method for quick finding of the information related to a specific mineral. In year 2014, 12 states each produced more than $2 billion worth of nonfuel mineral commodities. These States include --Arizona, Nevada, Minnesota, Texas, Utah, California, Alaska, Florida, Missouri, Michigan, Wyoming, and Colorado. Global commodity traders, economists, construction industry engineering executives, geologists, mining engineers, and statisticians my highly desire the information contained in this annual resource. It is highly recommended that academic libraries with geology and mining engineering programs, special libraries within these fields, and public libraries place an updated annual copy of this primary source work in their business/economic and reference collections.