Germanium Deposits in the United States

This data release provides data for the single site in the United States (U.S.) that has public record of germanium (Ge) production. Germanium, which is currently classified as a critical mineral in the U.S., is also extracted as a byproduct from deposits in Alaska, Washington, and Tennessee. However, there is no public information that documents germanium production from these deposits. Current annual production of refined germanium is led by China at 85,000 tons, while estimates place U.S. reserves near 2,500 tons. Reported production of germanium in the U.S. is limited to one site, the Apex mine in Washington County, Utah. The Apex mine produced gallium (Ga) and germanium as primary products during the mid-1980s. Since its closure, germanium recovery has been restricted to refining processes of ore concentrates and recycling of waste scrap both in and outside the U.S. (U.S. Geological Survey, 2020). As a part of the process set forth by Executive Order 13817, the USGS National Minerals Information Center (NMIC) identified germanium as a critical mineral (Department of the Interior, 2018) due to the import reliance and importance in the sectors of defense, manufacturing, and telecommunications (Fortier and others, 2018). Germanium is used for strategic, consumer, and commercial applications due to its high refractive index, transparency to infrared light, and properties as a semiconductor. Most notably, germanium is a major component in infrared devices, fiber optic cables, and PET plastics (Melcher and Buchholz, 2014). As of 2019, the U.S. maintains greater than 50% reliance on imported germanium from countries such as Belgium and China who were the main U.S. suppliers between 2015-2018. Germanium is imported to the U.S. as germanium metal and dioxide for consumption (U.S. Geological Survey, 2020). Some germanium is recovered from recycling of scrap during the manufacturing process, such as the manufacture of fiber-optic cables (Mercer, 2015).The element germanium largely occurs as a geochemical substitute in various sulfide minerals, primarily in the mineral sphalerite (ZnS), with minor inclusion in silicate minerals. The greatest germanium concentrations occur in Kipushi-type deposits, principally in oxidation zones of sulfide ore (Holl and others, 2007). The largest past producers of germanium from Kipushi-type deposits occurred in Kipushi, Democratic Republic of the Congo, and Tsumeb, Namibia. These deposits host 60 million tonnes (t) at 100-200 parts per million (ppm) Ge and 28 million t at 50-150 ppm Ge, respectively. Currently, germanium is produced as a byproduct of zinc-bearing ore deposits. Acid mine drainage may have elevated signatures of germanium because of germanium's strong association to sulfide minerals (Shanks and others, 2017). Germanium is also recovered from lignite and coal deposits worldwide (Melcher and Buchholz, 2014). 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. Production and resource information 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 germanium mineral deposit in this database is not meant to imply that the deposit is currently economic. 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. Department of the Interior, 2018, Final list of critical minerals 2018: Federal Register Notice 83 FR 23295, no. 97, p. 23295-23296, https://www.federalregister.gov/d/2018-10667. Fortier, S.M., Nassar, N.T., Lederer, G.W., Brainard, J., Gambogi, J., and McCullough, E.A., 2018, Draft critical mineral list-Summary of methodology and background information-U.S. Geological Survey technical input document in response to Secretarial Order No. 3359: U.S. Geological Survey Open-File Report 2018-1021, 15 p., https://doi.org/10.3133/ofr20181021. Holl, R., Kling, M., and Schroll, E., 2007, Metallogenesis of germanium-A review: Ore Geology Reviews, v. 30, p. 145-180, https://doi.org/10.1016/j.oregeorev.2005.07.034. Melcher, F. and Buchholz, P., 2014, Germanium, chap. 8 of Gunn, G., eds., Critical metals handbook: Chichester, UK, John Wiley & Sons, Ltd., p. 177-203, https://doi.org/10.1002/9781118755341. Mercer, C.N., 2015, Germanium-Giving microelectronics an efficiency boost: U.S. Geological Survey Fact Sheet 2015-3011, 2 p., https://doi.org/10.3133/fs20153011. Shanks, W.C.P., III, Kimball, B.E., Tolcin, A.C., and Guberman, D.E., 2017, Germanium and indium, chap. I 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. I1-I27, https://doi.org/10.3133/pp1802I. U.S. Geological Survey, 2020, Mineral commodity summaries 2020: U.S. Geological Survey, 200 p., https://doi.org/10.3133/mcs2020.