My search for the best cut 1.7ct has narrowed down to these four final candidates. Any thoughts on these?
[1] 1.76ct J-VS2 IGI Table 58% Crown 35.3 Pavilion 40.8 https://www.jamesallen.com/loose-diamonds/round-cut/1.76-carat-j-color-vs2-clarity-excellent-cut-sku-20962148 $6290
[2] 1.71ct J-VS2 GIA Table 56% Crown 35.0 Pavilion 40.8 https://www.jamesallen.com/loose-diamonds/round-cut/1.71-carat-j-color-vs2-clarity-excellent-cut-sku-19897074 $6150
[3] 1.76ct J-VS1 IGI Table 57% Crown 34.1 Pavilion 41.1 https://www.jamesallen.com/loose-diamonds/round-cut/1.76-carat-j-color-vs1-clarity-excellent-cut-sku-20778405 $5800
[4] 1.71ct J-SI1 GIA Table 60% Crown 33.5 Pavilion 40.8 https://www.jamesallen.com/loose-diamonds/round-cut/1.71-carat-j-color-si1-clarity-excellent-cut-sku-20858000 $6380
In my opinion [2] seems to have the cut closest to the Tolkowsky Ideal of 34.5/40.8, but I’m not sure what to think about the brownish tint. [1] comes seconds in the cut but is very yellow I suspect IGI inflated its color grade to from K/L to J. And according to JA customer service [4] is a bit off in symmetry. [3] only ended in GIA EX in the cut estimator due to too large pavilion.
Cut estimator locations and comments:
Diamond 1.76ct [1]: Intersection both GIA EX and AGS Ideal, almost AGS edge
Diamond 1.71ct [2]: Intersection both GIA EX and AGS Ideal, brownish tint/hue
Diamond 1.76ct [3]: Only GIA EX
Diamond 1.71ct [4]: Intersection both GIA EX and AGS Ideal, on both edge
Regarding [6], I don’t think you’ll notice any practical difference in the arrows.
Regarding [7], that one shows strain with strong fluorescence. At L color, you might consider this one [8] https://www.diamondscreener.com/ja/loose-diamonds/round-cut/1.73-carat-l-color-vs1-clarity-excellent-cut-sku-20411409. It reduces the fluorescence to medium with less strain.
“When a diamond is strongly fluorescent and also contains light-scattering structural defects, these producers of contrast loss seemingly combine to cause a noticeably milky or hazy appearance.” https://www.diamondscreener.com/diamond-fluorescence-evidence-based-questions-and-answers/#does-strong-fluorescence After further reading here I now understand your point with [2], [3], [4] and [7]. Great write-up! [8] is now my top choice.
Another one
[5] 1.70ct J-VS2 IGI Table 59% Crown 36.0 Pavilion 40.7 https://www.jamesallen.com/loose-diamonds/round-cut/1.70-carat-j-color-vs2-clarity-excellent-cut-sku-17223773 $6870 Only AGS Ideal corner