Formula: (Ca,Ce)(Th,Ce)(PO4)2 Monoclinic
Description: Cheralite is a very rare mineral found in granite and syenite pegmatites.
MARATHON COUNTY: A low thorium, high phosphorous cheralite is widespread in the larger pegmatite dikes of the Wausau Pluton. These are exposed in the “rotten granite” quarries in Sec. 19 and 20 T.28N R.7E and elsewhere south of Rib Mountain. The cheralite occurs as corroded crystals locally as much as 1.5 cm. in length. The crystals are reddish on the outside, but have white interiors (Falster, 1987). Locally hollowed “isolated yellow platelets or stacked aggregates of yellowish platelets” sometimes with a reddish eye were reported by Buchholz (1999b). Much of the cheralite in these deposits in cheralite-(Ce), which has been verified from the Wimmer #3 Pit and Koss Pit (Falster et al., 2000, Buchholz and Simmons, 2002).
— Micro-crystals of cheralite occur with fergusonite at the Summit Lake Mine, in the Stettin Complex, west of Wausau (Falster, 1992, personal communication).
WOOD COUNTY: Cheralite has been tentatively I.D., based on EDS analysis, as occurring with monzonite at the Frederick Schill Quarry, near Vesper (SW NW sec. 5 T.23N. R.4E.) (Buchholz, 1999).