| (2005) Mineral Resources Data System (MRDS), US Geological Survey. Norton, James J. (1964) Pegmatites and other Precambrian Rocks in the Southern Black Hills Rocks & Minerals: 67(6): 380-388. USGS Bull 380D Geology and mineral deposits of some pegmatites in the southern Black Hills, South Dakota. USGS Professional Paper 297E. |
Etta Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA