Robertsite

Robertsite, Ca₆Mn₉(PO₄)₉O₆(H₂O)₆·3(H₂O) (alternatively formulated Ca₂(Mn₃(PO₄)₃O₂)(H₂O)₃), is a secondary phosphate species named for Willard Lincoln Roberts (1923-1987), mineralogist and professor who taught 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 dark reddish brown to black in color.

External links

* [http://www.mindat.org/min-3431.html Mindat.org entry]

References

*cite journal
author = Frank C. Hawthorne
title = Structure and chemistry of phosphate minerals
journal = Mineralogical Magazine
year = 1998
volume = 62
issue = 2
pages = 141–164
url = http://minmag.geoscienceworld.org/cgi/content/abstract/62/2/141
doi = 10.1180/002646198547512
format = abstract page
*cite journal
author = Moore, P.B.
title = Isotypy of robertsite, mitridatite and arseniosiderite
journal = Amer. Mineral.
year = 1974
volume = B59
issue =
pages = 55–59
url =