The Diamond Creek REE Project covers approximately 421 hectares (1,040 acres) and is comprised of 52 unpatented mining claims. It is located in the Eureka Mining district, approximately 13 kilometers (8 miles) north-northwest of the town Salmon, Idaho. The REE mineralization at Diamond Creek is found in quartz veins over a large area approximately 3.2 km (2 mi) long and 0.8 km (0.5 mi) wide.
The area was historically prospected for gold until 1949 when its unique geologic setting was recognized by the USGS and the Idaho Geological Survey. In the early 1950’s the U.S. government sponsored country-wide exploration for nuclear power related raw materials. This campaign resulted in the discovery of thorium in areas of Lemhi County, including the REE occurrence in the Diamond Creek area.
The REE bearing veins of the Diamond Creek area are on the short list of the well-recognized and studied occurrences in the United States. In 1979, M.H.Staatz, of the U.S. Geological Survey (USGS) estimated an overall probable resource at Diamond Creek of approximately 70,800 metric tonnes of total rare-earth oxides, using an average grade of 1.22 percent (Table 1). Reported sample assays show REE oxide contents ranging from 0.59 to 5.51 percent. Additionally, three samples cut across one of the larger veins were assayed for gold, and contained 0.5, 2.4 and 11.9 grams per tonne (0.017, 0.07, and 0.348 ounces per ton).
At Diamond Creek, the gold and REE’s occur within the same veins, but it is not clear if the gold is genetically related to the REE mineralization. Some of the mineral pulses have gold, thorium, uranium, niobium, yttrium and REE’s. Niobium and gold are possible by-products that would add greatly to the economics of the recognized deposits in Diamond Creek.