Hard rock lithium in the USA
The Black Hills of South Dakota are famous for historic lithium mining dating back to 1898 when Li-bearing spodumene (contains up to 7% Li₂O), and amblygonite (contains up to 10% Li₂O) was first mined near the township of Custer.
IRIS controls the largest number of lithium claims in the Black Hills. Its South Dakota Project has a combined total land holding of approximately 42,287 acres across 2,056 lode claims and is comprised of the highly prospective and strategic.
- Dewy Project;
- Custer Project;
- Helen Beryl Project; and
- Ruby Project
which contain abundant outcropping LCT pegmatite swarms. These projects represent large areas of fertile lithium-cesium-tantalum (“LCT”)-pegmatites covering several historic lithium mines and numerous historical industrial mineral pegmatite mines.