Finally got the diamond''s report...how is it?

[Kissmark]

Okay how does this one sound? Anything alarming

SHAPE: ROUND
CUT: BRILLIANT
MEASUREMENTS: 6.70 - 6.74 x 4.18 mm

CARAT WEIGHT: 1.16 CARATS
COLOR GRADE: F
FLUORESCENCE: NONE

CUT: EXCELLENT
SYMMETRY: EXCELLENT
POLISH: EXCELLENT
CLARITY GRADE: VS1

ENHANCEMENTS (BESIDES CUT/POLISHING): NONE
TOTAL DEPTH PERCENTAGE: 62.2%
GIRDLE THICKNESS: MEDIUM TO SLIGHTLY THICK
TABLE SIZE PERCENTAGE: 55%
GIRDLE FINISH: FACETED
CROWN ANGLE: 35.5‹
CULET: NONE
PAVILION DEPTH PERCENTAGE: 43.0%

I tried to use the Cut Adviser for the first time, and it came out to be
Factor Grade
Light Return Very Good
Fire Excellent
Scintillation Very Good
Spread or diameter for weight Very Good

Total Visual Performance 1.9 - Excellent
within TIC range

 

[whatmeworry]

Looks great. How did it look to you? I''m starting to notice now that there seem to be quite a few Tiffany cuts with 35.5 crown angles and 43% depth. Wonder if that''s a trend.

 

[WorkingHardforSmallRewards]

Just for my own interest I wouldn't mind knowing the star and LGF numbers, just as I have taken an interest in trying to understand them a bit better. Also, it looks nice, I wouldn't mind trying out a little higher crown angle on my own diamond!

Also, alot of the tiffany's I have seen were right at 62.2% depth as well, which is a little surprising for me.

Any information on the types, location, and color of the inclusions? I suppose you have looked at it, but sometimes it takes the right lighting to bring it to your attention the first time from some odd angle, so I think its probably better to see them all with a loupe or at least know the above information when inspecting it so you can give a complete examination of it before completing the transaction.

 

[Garry H (Cut Nut)]

please use the pavilion angle and not depth % in HCA
It could change the result quite a bit

 

[WorkingHardforSmallRewards]

That is a pretty big difference in 40.7 to 40.5

40.7degrees yeilds HCA 2.0, 40.6degrees yields HCA 1.3 and 40.5 yields HCA .7


How reliable are the angles in the tiffany data gary? do they round much? (I imagine they have some very expensive machines anyway)?

 

[Kissmark]

Date: 7/4/2007 3:14:44 AM
Author: Garry H (Cut Nut)
please use the pavilion angle and not depth % in HCA
It could change the result quite a bit

Garry unfortunately the "Pavilion Depth Percentage" is all I was given on the report. I don''t know if they would have the angel if I request....

 

[Garry H (Cut Nut)]

It is very old fashioned to not give the angle.
This % data might be rounded and if the stone has a 43.2% pav depth and a medium culet then it could have a 41.2 degree pavilionand an HCA score over 3

 

[Viphan01]

Gary, If I may ask you a question related to HCA:

Do you think the HCA is a good tool to evaluate light return of a diamond? There is a good diamond (GIAXXX, and I was told it is H&A, but do not see the inscription of H&A on the GIA), but when I run the numbers using HCA (table=56%, depth=62%, crown angle=35.5, pavillion=40., I only get total visual performance of 2.6 (very good fire, light return, scintillation and spread). On the other hand, a diamond with 1.7 total visual performance (excellent fire, light return, scintillation and very good spread) and measurements of table=55.2%, depth=62.3%, crown angle=35.3 and pavillion=40.7, has very average H&A appeal. The question is, would you buy a diamond with H&A but lower score on HCA or a diamond with higher score on HCA but poor-average H&A appearance?


Thanks,

 

[WorkingHardforSmallRewards]

If you run some searches on this you will find alot of threads discussing similar topics. Look for threads on how to interpret HCA numbers and threads on the importance of Hearts and arrows. Remember, hearts and arrows is really about optical symmetry, not necessarily about light performance. At any rate, Gary has commented on this a number of times in many of the threads. Happy hunting!

 

[Garry H (Cut Nut)]

Date: 7/4/2007 9:43:06 AM
Author: Viphan01
Gary, If I may ask you a question related to HCA:

Do you think the HCA is a good tool to evaluate light return of a diamond? There is a good diamond (GIAXXX, and I was told it is H&A, but do not see the inscription of H&A on the GIA), but when I run the numbers using HCA (table=56%, depth=62%, crown angle=35.5, pavillion=40., I only get total visual performance of 2.6 (very good fire, light return, scintillation and spread). On the other hand, a diamond with 1.7 total visual performance (excellent fire, light return, scintillation and very good spread) and measurements of table=55.2%, depth=62.3%, crown angle=35.3 and pavillion=40.7, has very average H&A appeal. The question is, would you buy a diamond with H&A but lower score on HCA or a diamond with higher score on HCA but poor-average H&A appearance?


Thanks,

H&A''s virtually guarantees a level of symmetry that makes a higher hca score ''safer''.
HCA only helps with potential - it can not tell you about the actual diamond. Even so - a little digging (another topic) can make a stone like yours have less outer facet light return.
IOdeal-scope images solve these problems

 

[Regular Guy]

Date: 7/4/2007 3:14:44 AM
Author: Garry H (Cut Nut)
please use the pavilion angle and not depth % in HCA
It could change the result quite a bit

Garry, is this a point you and John Q may differ on?

Consider my understanding 4th hand. In a webinar he ran, I asked him if he regarded the rounding implied by an EGL % more egregious or less than the explicit rounding done by GIA...and he seemed to ignore the idea that a % was any less helpful than its converted angle.