Scientists studying rare earth and critical elements now have a solid foundation for future research, as detailed in a special volume of the Society of Economic Geologists. This review volume, featuring several papers authored and co-authored by the U.S. Geological Survey, provides a comprehensive review of the current state of knowledge for rare earth and critical elements in ore deposits.

In addition, on March 30th at 1:00 PM EDT, American Geosciences Institute (AGI) will co-host a webinar titled Underpinning Innovation: The Science and Supply of America's Critical Minerals and Materials. USGS speakers include Larry Meinert, the program coordinator of the USGS Mineral Resources Program and Steve Fortier, the director of the USGS National Minerals Information Center. In addition, Rod Eggert, the deputy director of the Critical Minerals Institute, Ames Laboratory will be a featured speaker.

This webinar is based on a March 3^rd Congressional briefing organized by AGI on behalf of the Mineral Science & Information Coalition. The webinar will address the efforts being taken at the federal level to ensure a steady supply of critical minerals and materials.

The special volume, entitled "Rare Earth and Critical Element in Ore Deposits," represents an important contribution to our understanding of where, how, and why individual critical elements occur and should be of use to both geoscientists and public policy analysts. While the papers in this volume provide an overview of the state of knowledge concerning the economic geology of rare earth and critical elements, they also demonstrate the lack adequate data on the occurrence of these elements in many deposit types.

Critical minerals and materials are key components of the innovation economy. Minerals are a part of almost every product we use on a daily basis, either as the raw materials for manufacturing processes or as the end products themselves. Advanced technologies for communications, clean energy, medical devices, and national security rely on raw materials from mines throughout the world.

The concept of element criticality is useful for evaluation of the fragility of commodity markets. This fragility is commonly due to a potential risk of supply disruption, which may be difficult to quantify because it can be affected by political, economic, geologic, geographic, and environmental variables. For instance, in 2010, China curtailed exports of rare earth metals and sparked major concern about the security of global supply chains for a range of vital minerals and materials.

Critical elements may be recovered either as primary commodities or as by-products from mining of other commodities. For example, nearly 90 percent of world production of niobium (Nb) is from the Araxá niobium mine (Brazil), whereas gallium (Ga) is recovered primarily as a by-product commodity of bauxite mining or as a by-product of zinc processing from a number of sources worldwide. Critical elements that are solely produced as by-product commodities pose a particular supply risk because their production is tied to other markets and thus fluctuations in their supply can be independent from their demand.

Rare earth elements are a focus of this volume because price spikes of these commodities over the past several years have created broad interest. As demonstrated in the papers in this volume, ore-grade enrichment of REEs can occur in a variety of deposit types.