American lithium treasure underground could last for centuries

The United States imports more than half of the lithium it needs and has only one operating mine. Although Australia leads global mining ahead of Chile and China, China controls much of the processing, leaving a large share of the world's lithium dependent on Chinese facilities before it reaches battery manufacturers.

That concentration has made lithium a critical mineral for the United States. The situation could change after American geologists identified major deposits in two Appalachian regions. The Southern Appalachians, mainly in North and South Carolina, contain about 1.43 million tons of lithium oxide. That would equal roughly 201 years of recent U.S. imports.

The Northern Appalachians, mainly in Maine and New Hampshire, contain about 900,000 tons. The combined estimate of 2.3 million tons could cover the equivalent of 328 years of current U.S. imports. Globally, the amount could support the production of 1.6 million grid batteries, 130 million electric vehicles, 180 billion laptops or 500 billion mobile phones. A publication in Natural Resources Research calculated that, at current demand, it represents 1,000 years of laptop production or about 60 phones for every person on Earth.

The deposits occur in coarse-grained igneous rocks called pegmatites, which contain the pale-green mineral spodumene. The formations crystallized more than 250 million years ago, which helps explain their presence in an ancient mountain range such as the Appalachians. But pegmatite deposits usually appear as numerous, small and scattered formations. That distribution raises production costs, complicates mining logistics and could create serious environmental problems.

The Appalachians are sparsely populated, especially in the north, but they are also highly valuable natural areas. Whether American businesses will want to develop the deposits remains uncertain, particularly while lithium remains more readily available and cheaper on global markets. Prices have swung sharply, from $4,470 per ton in 2000 to $59,430 in 2022, then down to $12,390 in 2024. They currently range from $21,000 to $23,600.