by wanderlost » Jul 24, 2004 I''ve read through the older posts about PGS certs. and just wanted to see if anyone had experience with buying diamonds with a PGS cert. There are mentions (in the old posts) that in a few cases the clarity grade decreased (which I would assume is rare) when submitting a PGS graded stone to GIA... has anyone else had this experience? Any other information about PGS would be great as well. Thanks.