1) Monoclinic mineral 2) Phosphate mineral
Found on
https://www.crosswordclues.com/clue/robertsite
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...
Found on
http://en.wikipedia.org/wiki/Robertsite
No exact match found.
