ABSTRACT Cheralite, (LREE,Ca,Th,U)(P,Si)O4, an intermediate member of the monazite group, between monazite, CePO4, and brabantite, CaTh(PO4)2, from the type locality has been re-analyzed by ICP-AES, ICP-MS, and LA-ICP-MS techniques. Unit-cell data have also been redetermined on material from the type locality. An empirical formula calculated on the basis of 16 oxygen atoms is: (REE1.638Ca1.130Th1.033U4+0.162Pb0.036Sc0.002)∑4.001 (P3.806Si0.235 )∑4.041O16. Unit cell data are: a- 6.756(2)Å, b-6.970(3)Å c-6.471(2)Å, β-103.89(3)°, V - 295.8Å3. Dmeas = 5.28(4) and Dcalc = 5.29. Measured optical properties are virtually identical to those reported by Bowie and Horne (1953). Associated honey to yellow-brown cheralite also occurs in the pegmatite, and contains more Fe and less U and Ca than the green cheralite.
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