Many of the fastest growing clean energy technologies, from batteries to solar panels to magnets, are made with materials that have unique chemical and physical characteristics, including magnetic, catalytic and luminescent properties. These materials -- which include some rare earth elements and are often called critical materials -- are essential to the clean energy economy and are at risk for supply disruptions. This map shows countries with significant supplies of rare earth elements, and existing mines, deposits, and occurrences of rare earth elements.