Strange numbers in a H&A report

[mastercut]

Hi,
a friend of mine bought second-hand an Amore ideal cut diamond (H&A by Mor bothers company). The stone has a GIA report from 2004 (so no cut details apart from 57% table, 62% depth, ex/ex polish/symmetry and medium-slightly thick girdle]. However the stone has an Amore certificate from 2008, there are these numbers: 57% table, 62% depth, 35 crown angle, 40.6 pavillion angle, 2.0-2.7% girdle. The girdle numbers looks strange to me, because 40.6 pavillion should give 43%, 35 degrees crown should give about 15% and with a 2.7% girdle that doesn´t make 62% depth at all.. What do you think?

 

[Dreamer_D]

Date: 1/13/2010 5:34:37 PM
Author:mastercut
Hi,
a friend of mine bought second-hand an Amore ideal cut diamond (H&A by Mor bothers company). The stone has a GIA report from 2004 (so no cut details apart from 57% table, 62% depth, ex/ex polish/symmetry and medium-slightly thick girdle]. However the stone has an Amore certificate from 2008, there are these numbers: 57% table, 62% depth, 35 crown angle, 40.6 pavillion angle, 2.0-2.7% girdle. The girdle numbers looks strange to me, because 40.6 pavillion should give 43%, 35 degrees crown should give about 15% and with a 2.7% girdle that doesn´t make 62% depth at all.. What do you think?

That isn''t how those numbers add up. I can''t recall what the correct way of working it out is, but someone will chime in soon.

 

[stone-cold11]

Depends on how the girdle is measured too. If GIA graded it from Med to Slightly Thick, it will be thickest at 4-5% instead of what the Amore cert said.

Reference:
https://www.pricescope.com/community/threads/girdles.66614/

 

[mastercut]

Yes, this is what I meant - it looks strange that GIA MED-STHK could give 2.0-2.7%. But if the girdle is really 2.0-2.7% this diamond doesn´t look ideal at all...

 

[stone-cold11]

I am thinking Amore measures the valleys of the girdle for the variation, while GIA's measurement is taken from the peaks. That should account for the difference. AGS will measure the thinnest of the valley and thickest of the peaks.