History of a stone, AGS in 2005, GIA in 2015

[nikolajkarpov]

Hi,

Bought this stone (Round, 2.007, H, VS1):

AGS - 6687708
GIA - 2171269039



So looks like stone was originally graded by AGS in 2005 and sold. After some time it got back to the market, probably it was polished from the sides since 3 things changed:

Crown Angle: 34.2 -> 34.5
Depth: 55.9 -> 56
Total Depth: 62.1 -> 62.3

Also however it was graded by AGS as AGS Ideal 0, GIA graded it as Excellent, Excellent, Very Good.

What do you guys think?

 

[John P]

Cool question.

No proportions were altered. Scan technology isn't perfect. Given error is circa ± 0.02 mm linear. GIA scanned the depth at 5.01 mm compared to AGS' older scan of 5.00 mm. Nothing grew it 0.01 deeper over time of course (wouldn't that be nice). GIA also rounds to nearest 0.5° on crown angle, so 34.5 is likely 34.3 or 34.4 rounded up. All within tolerance. All makes sense.

Appears to be some wear and tear along the way. Symmetry went from AGS Ideal to GIA VG. This indicates some impairment to facet lines, meet points or junctions in the interim.

 

[nikolajkarpov]

Thank you John, makes perfect sense.

One more question if you don't mind:

1. If you have to judge the price based on the certificates, I assume price based on GIA cert would be lower for 2-4k because of Symmetry and Fluorescence (from medium to strong)?

The reason I'm asking is that I bought it based on AGS cert, but when received I've found GIA inscription which pulled more interesting details on a current state and I'm not sure it's worth what I paid for it.





Thank you in advance!

 

[diamondseeker2006]

Are you within your return period? I'd want price based on the most recent grading definitely.

 

[nikolajkarpov]

Yes, I can return it. I'll get the appraisal on Tue, hope this will give some estimate.

 

[denverappraiser]

Use the most current data for your comps.

 

[diamondseeker2006]

Yes, I can return it. I'll get the appraisal on Tue, hope this will give some estimate.

Just be forewarned that many appraisals have inflated value. So your main objective would be confirmation of the GIA grading. Determine pricing based on stones with the same specs. We can help you if you want.