Tantalum Deposits in the United States

This U.S. Geological Survey (USGS) data release provides the descriptions of the only U.S. sites--including mineral regions, mineral occurrences, and mine features--that have reported production and (or) resources of tantalum (Ta). The sites in this data release have contained resource and (or) past production of more than 900 metric tons Ta metal, which was the approximate average annual consumption of Ta in the U.S. from 2016 through 2020. This dataset contains the Bokan Mountain deposit in Alaska and the Round Top deposit in Texas. Tantalum primarily occurs in the mineral tantalite, which may be found in carbonatites, alkaline granite-syenite complexes, and lithium-cesium-tantalum (LCT) pegmatites. The largest Ta deposits can be found in Australia, where the Greenbushes and Wodgina Mines have been producing Ta from pegmatites since the late 1880s. The Greenbushes is an LCT pegmatite deposit that contains more than 135 million metric tons of ore with an average grade of 0.022 percent Ta2O5. The Wodgina LCT pegmatite deposit contains more than 85 million metric tons of ore at a grade of 0.032 percent Ta2O5 (Schulz and others, 2017). In comparison, the largest Ta deposit in the U.S. is the Round Top deposit in Texas, which has reported resources of more than 480 million metric tons with an average grade of 67.2 grams per metric ton Ta2O5 (Hulse and others, 2019). There are no current U.S. producers of Ta. Tantalum is necessary for strategic, consumer, and commercial applications. Tantalum is highly conductive to heat and electricity and known for its resistance to acidic corrosion, thereby making this metal an ideal component for electronic capacitors, telecommunications, data storage, and implantable medical devices. In 2020, the U.S. was 100 percent net import reliant on Ta from countries such as China, Germany, Australia, and others. Tantalum is imported to the U.S. as ore and concentrate, metal and powder, as well as waste and scrap (U.S. Geological Survey, 2021). The entries and descriptions in the database were derived from published papers, reports, data, and internet documents representing a variety of sources, including geologic and exploration studies described in State, Federal, and industry reports. Resources extracted from older sources might not be compliant with current rules and guidelines in minerals industry standards such as National Instrument 43-101 (NI 43-101). The presence of a Ta mineral deposit in this database is not meant to imply that the deposit is currently economic. Rather, these deposits were included to capture the characteristics of the largest Ta deposits in the United States. Inclusion of material in the database is for descriptive purposes only and does not imply endorsement by the U.S. Government. The authors welcome additional published information in order to continually update and refine this dataset. Hulse, D.E., Malhotra, D., Matthews, T., and Emanuel, C., 2019, NI 43-101 preliminary economic assessment Round Top project, Sierra Blanca, Texas, prepared for USA Rare Earth LLC and Texas Mineral Resources Corp. [Filing Date July 1, 2019]: Gustavson Associates, LLC, 218 p., accessed October 17, 2019, at http://usarareearth.com/. Schulz, K.J., Piatak, N.M., and Papp, J.F., 2017, Niobium and tantalum, chap. M of Schulz, K.J., DeYoung, J.H., Jr., Seal, R.R., II, and Bradley, D.C., eds., Critical mineral resources of the United States--Economic and environmental geology and prospects for future supply: U.S. Geological Survey Professional Paper 1802, p. M1-M34, https://doi.org/10.3133/pp1802M. U.S. Geological Survey, 2021, Mineral commodity summaries 2021: U.S. Geological Survey, 200 p., https://doi.org/10.3133/mcs2021.