Tags: Chemical Substance, Mineral.
Robertsite Ca3(Mn3+)4[(OH)3 (PO4)2]2·3(H2O) (alternatively formulated Ca2(Mn3(PO4)3O2)(H2O)3) is a secondary phosphate mineral named for Willard Lincoln Roberts (1923–1987) mineralogist and professor at South Dakota School of Mines in Rapid City South Dakota. The type locality for Robertsite is the Tip Top mine Custer County South Dakota USA. Robertsite occurs at the Tip Top Mine as minute crystal aggregates and crusts found on quartz associated with triphylite.
