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diamond help- proportions

Liam-Spillane

Rough_Rock
Joined
Jul 17, 2011
Messages
21
My girl fiend wants a GIA RB stone with at least an I color (preferred G/H) and right around 3/4 carat and at least SI1 clarity. My budget it 4K - 4.5K tops including the basic solitaire setting 3-$400. I would truly appreciate help on this. I just want a stone that has good spread without taking away from the beauty of it. I know you can't say how great it is by the numbers, but please just let me know:
* Does any of the proportions raise a red flag?
* Does this sound like a fair price?

I saw the diamond in all types lighting, including a slightly cloudy day with no artificial lighting. The diamond really shines. I would say it is very brilliant while still maintaining great contrast, and only a very slight degree loss in fire vs the true ideal cut diamonds I saw. I just favored it since it looks slightly bigger and about $400 dollars cheaper than the two diamonds that fall within the true American ideal proportions. I placed a $500 dollar deposit to hold it. I'm no diamond expert, but I looked at 8 diamonds and spent 2 hours doing so. All were GIA excellent except two very good, they alo were F-I color and SI1- VS2. (price from2,900- 4,300)

GIA: .75 G VS2 BR
price $3,650 (diamond only- Barmakian's)
measurements 5.97-5.99 X 3.52

Table-60%
Depth- 58.8%
Crown angle- 32.5
Pavilion angle- 41.0
crown height 12.5%
pavilion height 43.5%
HCA- 1.3 TIC

cut grade- ex
symmetry/polish- ex/ex
cutlet- none
thin - med, faceted 3%
florescence- none
clarity characteristics- cloud / feather (nothing under the table)
 

kelpie

Ideal_Rock
Joined
Jan 8, 2008
Messages
2,362
Run away!
Depth should be 60-62.5
Table 54-58
Crown 34-34.5
Pavilion 40-40.8

But hey, maybe your eye is a better judge than numbers
 

dreamer_dachsie

Super_Ideal_Rock
Joined
Dec 16, 2007
Messages
24,364
The angles are complimentary. What is the lgf ratio? It is a number written in the longer facet on the pavilion of the diamond in the report. Will be something like 75 or 80. That number can also help balance the shallower crown, along with the slightly steeper pavilion the diamond has.

This is a stone where your eyes are a good judge; in absence of an ideal scope image we can't really tell you too much remotely. Depending on how the numbers were rounded it could be better or worse. You might want to look at it again comparing to more traditionally ideally proportioned stones, like an AGS0 stone perhaps, and hold it closer and further from your eyes and see if the center of the stone goes a little over dark compared to another.

But if you have seen it and like it and compared it to others, then I think it passes muster.
 

dreamer_dachsie

Super_Ideal_Rock
Joined
Dec 16, 2007
Messages
24,364
kelpie|1310932338|2970898 said:
Run away!
Depth should be 60-62.5
Table 54-58
Crown 34-34.5
Pavilion 40-40.8

But hey, maybe your eye is a better judge than numbers
Proportions outside those ranges can also be complimentary. That is the problem with using ranges like that, it is overly-strict and excludes a lot of potentially good cuts.
 

Liam-Spillane

Rough_Rock
Joined
Jul 17, 2011
Messages
21
I think the lgf is 75%. There is also a number on the report showing 50%, but I'm not sure what it is. (to the left of the table percentage on the top on the proprtions picture of the new GIA report.)
 

Stone-cold11

Super_Ideal_Rock
Joined
Sep 9, 2008
Messages
14,069
Yap, that is the lower half. The other number is for the star facet.

This stone is cut more towards brilliance light return, has a larger diameter compared to the the more balance ideal tolkowsky proportions, but sacrifice some fire performance for it. Personal preference on which type you prefer.
 

dreamer_dachsie

Super_Ideal_Rock
Joined
Dec 16, 2007
Messages
24,364
Stone-cold11|1310946958|2971047 said:
Yap, that is the lower half. The other number is for the star facet.

This stone is cut more towards brilliance light return, has a larger diameter compared to the the more balance ideal tolkowsky proportions, but sacrifice some fire performance for it. Personal preference on which type you prefer.
And before you freak out, the differences in terms of favouring one type of light return or another are subtle. You noted a slight decrease in fire when you compared it to the tolk style cuts. That is basically what SC is talking about. I wager you would see a similar compensation though in this diamond in brightness accross a variety of lighting conditions, particularly low light.
 

Liam-Spillane

Rough_Rock
Joined
Jul 17, 2011
Messages
21
I looked at the stone again and compared it to 3 other stones I orginally liked as well (2 were ideal proportioned.)

I brought 2 friends with me this time, one girl and one guy. They all picked the stone I choose, and I never told them which one picked. The reason according to them both was the stone looked bigger to them, and that is the same reason I chose it too. One of the stones was .82 and it still looked smaller side by side. They both said they couldn't tell a difference in the fire or brightness. I could, but again the diffences are so slight. Basically I struggled to see the difference in light preformance, but not the spread.


I'm pretty sure the reason the stone I choose looks bigger is b/c:

1) The shallower depth or just the proportions in general makes the outside edges brighter, giving the illusion of a bigger diamond.

2) The diamond diameter was also about 0.10 - 0.20 mm wider.

After really looking closely at them from all distances and lighting I feel really good just going for it. Diamond buffs may diagree with by logic, but spread really is more important than I even realized in my research. Also I saved $300-450 compared to the two ideal stones.
 

Stone-cold11

Super_Ideal_Rock
Joined
Sep 9, 2008
Messages
14,069
Yap, that's what most people will choose too unless you specifically want something else.
 
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