| Lat / long: | 43.85218, -103.61946 |
| Primary: | Feldspar, Beryllium, Mica, Lithium |
| Secondary: | Tantalum |
| Ore: | Amblygonite, Beryl, Columbite, Feldspar, Muscovite |
| Gangue: | Cleavelandite, Quartz, Sericite, Spodumene, Tourmaline, Triphylite, Uraninite, Uranophane |
| Orebody form: | IRREGULAR-SHAPED DIKE |
| Discovery year: | 1932 |
| Operation type: | Unknown |
| Production size: | Small |
| Development status: | Past Producer |
| First production started: | 1934 |
| Host rock: | Quartz Two-Mica Schist |
| Host type: | Mica Schist |
| Associated rock: | Pegmatite |
| Associated type: | Pegmatite |
| Structure: | Black Hills Uplift |
| Alteration processes: | Spodumene Is Highly Altered. Albite Has Replaced Microcline |
| MRDS | SD02291 |
| DEP | 10055678 |
| Reference | {Deposit:: U.S. BUREAU OF MINES, 1955, BLACK HILLS MINERAL ATLAS, SOUTH DAKOTA: PART 2, BUREAU OF MINES INFORMATION CIRCULAR 7707}{Deposit:: FISHER, D. JEROME, 1945, PRELIMINARY REPORT ON THE MINERALOGY OF SOME PEGMATITES NEAR CUSTER, SOUTH DAKOTA GEOLOGICAL SURVEY REPORT OF INVESTIGATIONS 50}{Deposit:: FISHER, D. JEROME, 1942, PRELIMINARY REPORT ON SOME PEGMATITES OF THE CUSTER DISTRICT, SOUTH DAKOTA GEOLOGICAL SURVEY REPORT OF INVESTIGATIONS 44}{Deposit:: ROBERTS, W.L., AND RAPP, GEORGE, 1965, MINERALOGY OF THE BLACK HILLS, SOUTH DAKOTA SCHOOL OF MINES AND TECHNOLOGY BULLETIN 18} |
| Reporter | Barari, Rachel A. |