English: These specimens show yellowish nodules included in a feldspar matrix. First SEM-EDS analysis have yielded a phosphate of Th and Ca, with minor Pb. XRD has shown patterns of "bravantite", the old name for cheralite and brockite. The chemical base formula for these species are: grayite (Th,Pb,Ca)(PO4)·H2O; cheralite CaTh(PO4)2; brockite (Ca,Th,Ce)(PO4)·H2O. REE has not been found in EDS.
We could say that this yellow nodules belongs from altered monazite, formed by mixed species cheralite-grayite, with minor brockite. Accompanied in matrix by meta-autunite.
From: Brabant Farm 168, Karibib, Erongo, Namibia.
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
Uploaded a work by Joan Rosell from https://www.rosellminerals.com/en/minerales.php?idmineral=1979&yng=1&nomb_mine=Grayite&id_pais=&local_mine=&cons_gral= with UploadWizard