Wikipedia
Fluorcarmoite-(BaNa)
Fluorcarmoite-(BaNa) is a rare phosphate mineral, belonging to arrojadite group, with the formula Ba[]NaNa[]CaMgAl(PO)(POOH)F. It is a barium-rich member of the group, as is arrojadite-(BaNa), arrojadite-(BaFe), fluorarrojadite-(BaFe) and an unapproved species ferri-arrojadite-(BaNa). The "-(BaNa)" suffix informs about the dominance of the particular elements (here barium and sodium) at the corresponding structural sites.