Graphite deposits in the United States

This U.S. Geological Survey (USGS) data release provides the descriptions of 10 U.S. sites that include mineral regions, mineral occurrences, and mine features that contain enrichments of graphite. To be included in this data release, sites must have a contained resource and (or) past production of more than 1,000 metric tons of graphite, which is approximately 3 percent of the average annual U.S. consumption of graphite from 2016 through 2020. Sites in this dataset occur in Alaska, Alabama, Colorado, Montana, New York, Pennsylvania, and Texas. There are known graphite occurrences in California, Connecticut, Georgia, Michigan, New Hampshire, New Jersey, North Carolina, Rhode Island, and Wyoming that have not been included in this database because contained resource and (or) production of graphite were not found above our cutoff in the public domain for these areas.

Graphite is considered a critical and strategic mineral because of its essential applications in the aerospace and energy sectors (Robinson and others, 2017). Graphite is used in batteries, brake linings, lubricants, powdered metals, refractory applications, and steelmaking (U.S. Geological Survey, 2021). In 2020, the U.S. was 100 percent net import reliant on graphite from countries that included China, Mexico, Canada, and India (U.S. Geological Survey, 2021). Graphite has not been produced in the U.S. since the 1950s.

Graphite occurs in the U.S. as disseminated flake graphite deposits and as graphite veins. Globally, most currently mined flake graphite deposits contain at least 8 to 12 percent graphitic carbon in deposits larger than 0.5 million metric tons (Robinson and others, 2017). In comparison, the Graphite Creek deposit in Alaska contains a measured and indicated resource of more than 10 million metric tons with 7.8 percent graphite plus an inferred resource of more than 90 million metric tons with 8 percent graphite (King and others, 2019). Graphite One Inc. plans to decide whether to move the Graphite Creek deposit into production after an updated prefeasibility study is completed in early 2022.

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 graphite 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 graphite 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.

King, N., Valorose, C., and Ellis, W., 2019, 2019 NI 43-101 mineral resource update for Graphite Creek, Seward Peninsula, Alaska, USA, prepared for Graphite One Inc. [Filing date March 26, 2019]: Alaska Earth Sciences, Inc., 258 p., accessed February 6, 2020, at http://www.sedar.com.

Robinson, G.R., Jr., Hammarstrom, J.M., and Olson, D.W., 2017, Graphite, chap. J 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. J1-J24, https://doi.org/10.3133/pp1802J.

U.S. Geological Survey, 2021, Mineral commodity summaries 2021: U.S. Geological Survey, 200 p., https://doi.org/10.3133/mcs2021.