Latitude: 43°42'46"N
Longitude: 103°41'49"W
A beryl mine located in sec. 7, T.4S., R.4E., at Fourmile, SW of Custer. Operated chiefly in the 1940's (WWII).
Mineralization is an irregular, oval, zoned pegmatite body in quartz-mica schist.
Workings include a large open cut.
Mineral List
35 entries listed. 24 valid minerals.
The above list contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please
register so you can add to our database. This locality information is for reference purposes only. You should never attempt to
visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders
for access and that you are aware of all safety precautions necessary.
References
Rocks & Minerals: 18: 207.
Meeves, H., et al (1966), Reconnaissance of beryllium-bearing pegmatite deposits in six western states, U.S. Bureau of Mines Information Circular 8298: 32 (Table A-1).
Rocks & Minerals: 60: 117.
Moore, P. B., 2000, Analyses of Primary Phosphates from Pegmatites in Maine and Other Localities, in V. T. King (editor), Mineralogy of Maine. Mining History, Gems, and Geology, Maine Geological Survey, Augusta, Maine, p. 333-336.
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.
Mineral and Locality Search
