Spodumene from selected localities.
USA | |
| Rocks & Minerals: 60: 117; Meeves, H., et al (1966), Reconnaissance of beryllium-bearing pegmatite deposits in six western states, US Bur. Mines Info. Circ. 8298: 32 (Table A-1).; Staatz, M. H.; Page, L. R.; Norton, J. J.; Wilmarth, V. R. (1963) Exploration for beryllium at the Helen Beryl, Elkhorn, and Tin Mountain pegmatites, Custer County, South Dakota. USGS Prof. Paper 297C. |
South Dakota SMT Bull 18 Roberts and Rapp "Mineralogy of the Black Hills"; Staatz, M. H.; Page, L. R.; Norton, J. J.; Wilmarth, V. R. (1963) Exploration for beryllium at the Helen Beryl, Elkhorn, and Tin Mountain pegmatites, Custer County, South Dakota. USGS Prof. Paper 297C. | |
U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia. | |
USGS Prof Paper 297F |
Helen Beryl Mine, Fourmile, Custer Mining District, Custer County, South Dakota, USA