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7 x 4 x 2.5 cm - Sm Cabinet 
Ca9Mg(PO4)6(PO3F) (RRUFF)
Tip Top mine, Custer Co., South Dakota, United States

An excellent specimen of rich clear rhombs of Bobdownsite on pink orthoclase matrix. We have hyphenated it with Whitlockite as the jury is still out on this identification. It may be both. Raman analyses at the RRUFF project has thus shown all Whitlockites from the Tip Top mine to be Bobdownsite. But there is a chance that fluorine maybe detected by inclusions of fluorapatite in the crystals. It is very difficult to distiguish F from OH with EDS without doing a polished section. Whatever the case, it is academic and not really important in the overall scheme and parageesis of pegmatitic mineralogy (or is it?). We look forward to your comments. You will find a good thread on Mindat.

A case in point: Look close at these photos. There are sprays of white apatite scattered about the surfaces of the Bob-Whit xls. These may be carbonate apatite but may contain Fluorine to some degree.

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