n 1996 I purchased a GIA certified diamond .91 carats E color VVS1 clarity Good cut.
I just had the same diamond regraded. The new GIA certificate for the Same Stone claims it is I color, VS2 clarity, good cut.
Why is there such a difference in the grade? I thought the reason you purchased a graded diamond was because the quality was guaranteed?
The new source is a reseller and I am not sure I trust their certification process? When I asked about the difference, I was told that older GIA Certificates were done using different processes and were not as reliable as current certifications, is that true?