Okay, I''ve lurked in the shadows long enough. Time to register and show myself.
This post touches on some of the material covered in "A day at Tiffany''s with the I-Scope..."
https://www.pricescope.com/community/threads/a-day-at-tiffanys-with-the-i-scope.69733/
I am a beginner at stone assessment. I have silently been immensely grateful to find the advice and debate on this site, and would be openly even more so if the assembled company were to respond here. I am looking at Tiffany engagement rings, not because my lady demands it (seemingly the most common motivation, judging by posts I have read) but because I am a time-constrained beginner, and I am (almost) willing to rely on a brand to reduce the time required to find a good stone and a nice setting.
I have been using the HCA calculator as an independent view (Garry I just ordered my I-scope today - looking forward to it). On five stones currently in stock at Tiffany''s stores, I have the data below on 5 round cut diamonds. By the way, consistent with other posts, there is no external certificate available.
Stone 1
Size: 1.01
Colour: D
Clarity: IF
Depth: 62.3
Table: 57
Crown angle: 35.5
Pavilion angle: 41.1
HCA: 4.5
Light return: G
Fire: G
Scintillation: G
Spread: VG
Stone 2
Size: 1.02
Colour: E
Clarity: IF
Depth: 61.7
Table: 58
Crown angle: 35.4
Pavilion angle: 41
HCA: 3.7
Light return: G
Fire: G
Scintillation: G
Spread: VG
Stone 3
Size: 1.38
Colour: F
Clarity: VVS1
Depth: 61.2
Table: 59
Crown angle: 35.2
Pavilion angle: 41
HCA: 3.3
Light return: VG
Fire: G
Scintillation: G
Spread: VG
Stone 4
Size: 1.03
Colour: D
Clarity: IF
Depth: 62.6
Table: 57
Crown angle: 35
Pavilion angle: 41.1
HCA: 3.1
Light return: VG
Fire: VG
Scintillation: G
Spread: VG
Stone 5
Size: 1.38
Colour: E
Clarity: VVS1
Depth: 60.4
Table: 59
Crown angle: 33.5
Pavilion angle: 41.1
HCA: 2.1
Light return: VG
Fire: VG
Scintillation: VG
Spread: VG
I have assumed no culet in all stones, as I did not get this information from the Tiffany stores.
Although a statistician would say I do not nearly have a reliable sample size, I see a possible trend here. Stones 1-4 have HCA scores of 3 or above (I don''t think I am doing anything schoolboyishly wrong with the HCA). They all seem to fit a reasonably tight tolerance of crown angle about 35% and pavilion angle about 41%. By HCA standards, I think this is slightly steep/deep to get a score of sub 2.0.
Stone 5 is the exception, and I think the tighter HCA of 2.1 is introduced by the shallower crown angle of 33.5%.
The consistency of the dimensions of stones 1-4 suggests to me that this is intentional. Tiffany are a world leading jeweller, and I expect they employee some of the best craftsmen in the trade (although that could just be the branding speaking through me - haha!). These are all high quality stones by way of colour and clarity, so commonsense suggests to me that Tiffany would make sure the cut tolerances were at the highest end of their scale. In short,if they live up to their brand, this should be intentional - if they wanted to target a shallower cut, they could.
Which leads me to the following questions.
1. Is Tiffany''s ideal cut biased towards more steep/deep than HCA or am I smoking something?
2. What explains this? Is it a limitation of the HCA, a feature of Tiffany''s ideal cut, or both?
3. What impact does it have on fire and brilliance?
4. Am I splitting hairs? Should I just build a bridge and get over it?
Further, if you''re still reading, I am thoroughly open to suggestions on sourcing a ring. I am HK based, and have been looking at local big brand jewellers - Bulgari, De Beers, Tiffany, etc, and also local jewellers. I can get to London for a ring, but would have difficulty making it to a US vendor.
Thanks in advance for your time
This post touches on some of the material covered in "A day at Tiffany''s with the I-Scope..."
https://www.pricescope.com/community/threads/a-day-at-tiffanys-with-the-i-scope.69733/
I am a beginner at stone assessment. I have silently been immensely grateful to find the advice and debate on this site, and would be openly even more so if the assembled company were to respond here. I am looking at Tiffany engagement rings, not because my lady demands it (seemingly the most common motivation, judging by posts I have read) but because I am a time-constrained beginner, and I am (almost) willing to rely on a brand to reduce the time required to find a good stone and a nice setting.
I have been using the HCA calculator as an independent view (Garry I just ordered my I-scope today - looking forward to it). On five stones currently in stock at Tiffany''s stores, I have the data below on 5 round cut diamonds. By the way, consistent with other posts, there is no external certificate available.
Stone 1
Size: 1.01
Colour: D
Clarity: IF
Depth: 62.3
Table: 57
Crown angle: 35.5
Pavilion angle: 41.1
HCA: 4.5
Light return: G
Fire: G
Scintillation: G
Spread: VG
Stone 2
Size: 1.02
Colour: E
Clarity: IF
Depth: 61.7
Table: 58
Crown angle: 35.4
Pavilion angle: 41
HCA: 3.7
Light return: G
Fire: G
Scintillation: G
Spread: VG
Stone 3
Size: 1.38
Colour: F
Clarity: VVS1
Depth: 61.2
Table: 59
Crown angle: 35.2
Pavilion angle: 41
HCA: 3.3
Light return: VG
Fire: G
Scintillation: G
Spread: VG
Stone 4
Size: 1.03
Colour: D
Clarity: IF
Depth: 62.6
Table: 57
Crown angle: 35
Pavilion angle: 41.1
HCA: 3.1
Light return: VG
Fire: VG
Scintillation: G
Spread: VG
Stone 5
Size: 1.38
Colour: E
Clarity: VVS1
Depth: 60.4
Table: 59
Crown angle: 33.5
Pavilion angle: 41.1
HCA: 2.1
Light return: VG
Fire: VG
Scintillation: VG
Spread: VG
I have assumed no culet in all stones, as I did not get this information from the Tiffany stores.
Although a statistician would say I do not nearly have a reliable sample size, I see a possible trend here. Stones 1-4 have HCA scores of 3 or above (I don''t think I am doing anything schoolboyishly wrong with the HCA). They all seem to fit a reasonably tight tolerance of crown angle about 35% and pavilion angle about 41%. By HCA standards, I think this is slightly steep/deep to get a score of sub 2.0.
Stone 5 is the exception, and I think the tighter HCA of 2.1 is introduced by the shallower crown angle of 33.5%.
The consistency of the dimensions of stones 1-4 suggests to me that this is intentional. Tiffany are a world leading jeweller, and I expect they employee some of the best craftsmen in the trade (although that could just be the branding speaking through me - haha!). These are all high quality stones by way of colour and clarity, so commonsense suggests to me that Tiffany would make sure the cut tolerances were at the highest end of their scale. In short,if they live up to their brand, this should be intentional - if they wanted to target a shallower cut, they could.
Which leads me to the following questions.
1. Is Tiffany''s ideal cut biased towards more steep/deep than HCA or am I smoking something?
2. What explains this? Is it a limitation of the HCA, a feature of Tiffany''s ideal cut, or both?
3. What impact does it have on fire and brilliance?
4. Am I splitting hairs? Should I just build a bridge and get over it?
Further, if you''re still reading, I am thoroughly open to suggestions on sourcing a ring. I am HK based, and have been looking at local big brand jewellers - Bulgari, De Beers, Tiffany, etc, and also local jewellers. I can get to London for a ring, but would have difficulty making it to a US vendor.
Thanks in advance for your time