Where is Ytterium in apatitic marine sediments?

Having figured out where is Cerium, we wanted to know if Yttrium, which is much more abundant in fluoroapatite, is co-located with it or not. In our latest research on lanthanides in fluoroapatite, published in Chemistry of Materials, we demonstrate that Y is not in the same chemical environment as Ce. There are no Y aggregates detectable by EXAFS. Instead, Y seems to be incorporated in the amorphous coating of the apatite crystals.