South Dakota · Custer County
Occurrence
Friday Lode
Custer County, South Dakota, United States
Mica
Feldspar
Beryllium
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USGS source ↗
Commodities
Primary
Mica, Feldspar
Secondary
Beryllium
Commodity type
B
Deposit
Deposit size
N
Workings
Surface
Orebody form
KNOB-SHAPED
Materials
Ore minerals
Beryl, Mica
Gangue
Quartz, Tourmaline
Geology
Host rock
Schist · Schist
Associated rock
Pegmatite · Granite;Pegmatite
Alteration
Feldspar Is Iron Stained
Economic & production
Development status
Occurrence
Identification
Deposit ID
10010792
MRDS ID
D004766
Region
NA
Data score
C
Coordinates
43.77774, -103.65085
References
U. S. BUREAU OF MINES, 1955, BLACK HILLS MINERAL ATLAS, SOUTH DAKOTA: PART 2, BUREAU OF MINES INFORMATION CIRCULAR 7707