South Dakota · Custer County
Occurrence
Keystone Lode
Custer County, South Dakota, United States
Mica
Beryllium
Lithium
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USGS source ↗
Commodities
Primary
Mica, Beryllium, Lithium
Commodity type
B
Deposit
Deposit size
N
Materials
Ore minerals
Amblygonite, Beryl, Muscovite
Gangue
Albite, Hornblende, Microcline, Pyrrhotite, Quartz
Geology
Host rock
Pegmatite
Associated rock
Pegmatite
Economic & production
Development status
Occurrence
Identification
Deposit ID
10055768
MRDS ID
SD02513
Region
NA
Data score
B
Coordinates
43.7419, -103.70168
References
USGS PP 247, P. 141USBM INFO CIRC 7707, P. 120SDSMT BULL 18