Oldish GIA ID & Origin report?

[Rad_Fan]

How accurate would it be for a corundum given that gem treatments have changed over the past 20 years?

 

[marymm]

If the stone itself matches up to the GIA report and thus is at least as old as the GIA report date, why would anyone perform additional treatments on the gem?

Or, do you mean new tests detecting gem treatment have developed since the date of that report, such that if the gem were to be re-examined/re-tested, previously undetected treatment would now be identified?

In any case, at 20 years out, I'd probably request the purchase be conditional on a new GIA report, with full refund should the new report not match the results of the prior GIA report.

 

[chrono]

If it's something I already own, I would not send for an updated lab memo.
If I am selling, I will send it off if the potential buyer requests it (good sized / expensive stone).
If I am the buyer, I will definitely request one if past a certain price point that I am comfortable with