5533 Robertsite, Montgomeryite, Tip Top Mine (Tip Top pegmatite), Fourmile, Custer District, Custer Co., South Dakota, USA October 5, 2019 Steve North and Central Americas South Dakota United States Type Locality for robertsite. Ex John Lewis collection.
Europe Spain 1690 Montgomeryite, Santa Maria de Montcada, Barcelona, Catalonia, Spain September 22, 2019
North and Central Americas South Dakota United States ncat JP345 Montgomeryite, Whitlockite, Fluorapatite, Tip Top Mine (Tip Top pegmatite), Fourmile, Custer District, Custer Co., South Dakota, USA January 27, 2023
