I purchased my engagement ring from Tiffany a few years back and the diamond came with both Tiffany cert. and GIA cert (old format without cut grade). The cut grade is "excellent" on the Tiffany cert. Recently I obtained an updated GIA cert (new format with cut grade) for the same diamond and the GIA cut grade is "very good" on the GIA cert. I noticed there is one discrepancy on the Tiffany vs. GIA cert in terms of the "pavilion depth": 42.8% on Tiffany's vs. 42.5% on GIA's (GIA cert also shows pavilion angle of 40.6 degree but that figure is not available on the Tiffany cert).
Questions:
1) Is there a formula for calculating pavilion depth based on pavilion angle?
2) How significant is the 0.3 difference on the pavilion depth?
3) Who likely made an error on the pavilion depth (Tiffany or GIA)?
4) Should I approach Tiffany for a re-cert (I believe Tiffany's new cert. format now includes pavilion angle as well)? What are the chances that Tiffany would entertain such a request?
Any suggestion would be greatly appreciated!
P.S. I put the #'s through HCA and all three combinations produced favorable TIC results:
Depth %: 61.1
Table %: 55
Crown angle: 35
1) Pavilion depth: 42.8 (Tiffany)
2) Pavilion depth: 42.5 (GIA)
3) Pavilion angle: 40.6 (GIA)
Culet %: 0 (NONE)
Resulting TIC:
1) 0.6 (Tiffany)
2) 0.6 (GIA)
3) 0.8 (GIA)
Questions:
1) Is there a formula for calculating pavilion depth based on pavilion angle?
2) How significant is the 0.3 difference on the pavilion depth?
3) Who likely made an error on the pavilion depth (Tiffany or GIA)?
4) Should I approach Tiffany for a re-cert (I believe Tiffany's new cert. format now includes pavilion angle as well)? What are the chances that Tiffany would entertain such a request?
Any suggestion would be greatly appreciated!
P.S. I put the #'s through HCA and all three combinations produced favorable TIC results:
Depth %: 61.1
Table %: 55
Crown angle: 35
1) Pavilion depth: 42.8 (Tiffany)
2) Pavilion depth: 42.5 (GIA)
3) Pavilion angle: 40.6 (GIA)
Culet %: 0 (NONE)
Resulting TIC:
1) 0.6 (Tiffany)
2) 0.6 (GIA)
3) 0.8 (GIA)