In Chicago call Professional Gem Sciences, or PGS and speak with them. They may do what you need or can recommend someone locally that can probably help you.------------------
David Atlas
Accredited Gem Appraisers
I was not able to find any info on PGS in Chicago. Do you have any other info on them? P.S. I would appreciate any feedback on the questions that I posted in the Stone Advice Folder.Thanks