Hello All, I am hoping to obtain some reliably dated (i.e. by TIMS) and preferably old xenotime and garnet (ugrandite) to use as reference materials for U-Pb geochronology by LA-MC-ICP-MS. I have a good inventory of U-Pb RMs for many other minerals and would be happy to share some of what we have in exchange. Don't hesitate if the potential RMs is/may be heterogeneous on some scale, I don't mind doing a fairly thorough characterization of that by BSE imaging and targeted in-situ analyses, and potentially collaborate on a RM publication in the future. *For the xenotime:* Paleoproterozoic and older (ideally Archean) specimens are needed. Small grains are ok, as we commonly use a ~10 um spots size. *For the garnet:* Older is better as well, but anything with a good TIMS age on it (that's not actually dating the zircon/monazite inclusions) will be of use. These grains would need to be >50 um, but that shouldn't be too much of a problem for Grt. Thanks in advance and apologies for cross postings. Cheers -- Jeff ********************************************************** *Jeffrey H. Marsh* Research Associate & Director MERC Isotope Geochemistry Laboratory Metal Earth, Mineral Exploration Research Centre (MERC), Laurentian University 935 Ramsey Lake Rd, WGMC 8th Floor, Sudbury, ON P3E 2C6 T: 705.675.1151 <(705)%20675-1151> l F: 705-671-3855 <(705)%20671-3855> l jmarsh@laurentian.ca https://merc.laurentian.ca/research-facilities -- CONFIDENTIALITY NOTE <https://laurentian.ca/confidentiality> - AVIS: COURRIEL CONFIDENTIEL. You can view the confidentiality terms at https://laurentian.ca/confidentiality <https://laurentian.ca/confidentiality>. Notre avis de confidentialité est disponible au site https://laurentienne.ca/avis <https://laurentienne.ca/avis>