It took me awhile to figure out how to download the papers from the Academia site (gawd, what what a mess, it had be gibbering like a chimp - not to mention the privacy issues). But they're quite interesting and informative.

"Alison Carter" seems to be the name necessary to search on from the Home page in order to actually be able to download the PDFs.

https://www.academia.edu/233708/LA-ICP-MS_Analysis_of_Agate_and_Carnelian_Analysis_of_Geological_Sources_from_Central_South_and_Southeast_Asia_and_Beads_from_Iron_Age_sites_in_Cambodia

https://www.academia.edu/355169/INAA_of_agate_sources_and_artifacts_from_the_Indus_Helmand_and_Thailand_Regions