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50 hearts and 75 lower half..?

qui499kyl

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Hi all,

Thanks for your help in picking out diamonds earlier this week. I was reading our diamonds GIA report and its 50/75. I'm reading that's not the best, based on what I can find on the Internet. I'm not dumb, yet I'm not fully able to grasp the concept of what's the best combination. The other stone we sent back two weeks ago was a 50/80 and sparkled a ton. I'm worried 65 will have fat arrows and won't be ... What's the likelihood of this stone being less than optimal?? It's delayed now due to weather, so I have a day to reconsider
 

John P

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Re: 50 stars and 75 lower half..?

qui499kyl|1450955816|3965694 said:
Hi all,

Thanks for your help in picking out diamonds earlier this week. I was reading our diamonds GIA report and its 50/75. I'm reading that's not the best, based on what I can find on the Internet. I'm not dumb, yet I'm not fully able to grasp the concept of what's the best combination. The other stone we sent back two weeks ago was a 50/80 and sparkled a ton. I'm worried 65 will have fat arrows and won't be ... What's the likelihood of this stone being less than optimal?? It's delayed now due to weather, so I have a day to reconsider
I trust you're referring to an average star length of 50% (not hearts) and average lower half length of 75%. Those are appropriate for many round-brilliant proportions-sets. What are the other measurements?

Table %, average Crown-Angle, average Pavilion-Angle, and how consistently those groups were cut inside the averages is more critical to how a diamond will perform. If the primary geometry is returning light robustly the lower halves and stars can fine tune the character of that performance. Depending on those primary numbers, 75% lower halves (which is a rounded number if you're looking at a GIA Report) could be terrific, just fine, or problematic.
 

diamondseeker2006

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Given a choice, I will always choose 75-76!

1218316649 GIA number
1.7ct VVS1 H, medium fluoro
35/40.8 CA/PA
61.6 depth
56 table
7.64x7.68x4.72mm

Great stone. Would you PLEASE stop worrying????? :))
 

John P

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Say DS... You know with the GIA Report that could be anywhere from 73%-77%, right?

OP: No worries. I'm teasing my friend.

(now I'm going to get coal in my stocking)
 

diamondseeker2006

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John Pollard|1450990313|3965890 said:
Say DS... You know with the GIA Report that could be anywhere from 73%-77%, right?

OP: No worries. I'm teasing my friend.

(now I'm going to get coal in my stocking)

Lol! Well, for those who buy sight unseen, we just have to go with the only info we have. He's been worried about a lot of things besides lgf's. I just want the poor girl to get her ring! ;)) :lol:
 

qui499kyl

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Messages
154
Thanks everyone. Lol. I know I've been excessively worried about a lot of things!! It seems the nerves of proposing are manifesting in my hunt for the perfect diamond. Go figure, it could be worse... At least she will get something great from all of my worrying! So I am keeping the current stone, and have a backup on reserve at BN with 80% versus 75 (you know just in case it's really a 73, rounded...) just kidding, kind of. I've never been so perfectionistic about anything before in my life. It's crazy. Anyway, thank you all and merry Christmas / happy holidays!!
 

qui499kyl

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Dec 10, 2015
Messages
154
Same question for this stone. It's similar to the 1.7 yet different. It's my backup stone on reserve until this ring gets here..

1.50ct
Vs1, F Gia triple x
7.39x 7.37 x 4.53 mm
61.3 depth
57 table
35/40.8 ca/pa
Gia 2171344970
strong blue fluorescence checks out ok, no haziness Etc.

50 top/75 lower girdle

Thanks in advance!
 

diamondseeker2006

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That one is similar, and without pictures or ASET images, we can't have any idea if one is slightly better than the other. But you need to stick with the 1.7. She wants the larger stone! She liked H color, too! I like the slightly larger lgf's better. But trust me, they are still small!

I really respect guys that care so much to get the best diamond, truly. The ones who worry me are the ones trying to buy the cheapest diamond they can find even if it is a poor quality stone.

Here's my 1.65 with the 75 lgf's. I don't have a distance shot, but truly, you aren't going to be able to tell a lot of difference when you look at diamonds in real life viewing.

_35791.jpg
 

qui499kyl

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Messages
154
Is this one better...

It's 1.6 (I can't see the difference between 1.6 and 1.7)
But it's $1500 cheaper so I could get a nicer setting too.

It's E VS2 strong Fluoro
60.9 depth
56 table
33.5/41 CA/PA
50 / 80 lower girdle
Medium girdle all the way around
7.56x7.58x4.61

I think I'm Getting this one instead if you all agree...


Thoughts?? Color is better, clarity is "worse", measurements are entirely different.
 

diamondseeker2006

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I'll have to tell you, there are a lot more people who will frown upon strong blue fluorescence in a colorless stone than will frown on H color. No, I would not buy that one. Crown angle needs to be 34-35. I wouldn't ever choose 80 lgfs. The stone you have ordered is better.

One thing is, H color can show yellow when the diamond is not graded by GIA or AGS. MANY of those girls on wedding bee probably have diamonds graded by EGL or worse labs. Those color grades are worthless. So stop worrying about the color! She already liked the 1.3 H you ordered other than you decided to go larger!!!
 

qui499kyl

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Messages
154
Thank you! Ok, for some reason I thought 80 was better than 75, but I guess not. I read it makes the diamond more sparkly or brilliant but I guess it depends on the rest of the stone
 

diamondseeker2006

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qui499kyl|1451059537|3966119 said:
Thank you! Ok, for some reason I thought 80 was better than 75, but I guess not. I read it makes the diamond more sparkly or brilliant but I guess it depends on the rest of the stone

That is just absolutely not true. Many of us have sought out old european cutting because the lower facets are even larger than 75!!! But 75 is still tiny when you look at the diamond. Did you see my picture of my diamond with 75 lgf??? It is a gorgeous stone and so much prettier than one with splinter size facets! Bigger flashes of light!!! (but still tiny when actually looking at a 7.6mm stone!)
 

diamondseeker2006

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Really, I never would recommend D-F color when a budget is not unlimited. The only exception is that in certain cultures, colorless is expected. When size is important to the recipient, G-H color is the prime choice, in my opinion, but many here go for I-J to maximize size.
 

John P

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I began writing this and, coming back, see DS has provided her usual solid advice. Some of the below may be redundant, but there's also specifics about context as it relates to some questions, our abilities and our limitations.

qui499kyl|1451052282|3966101 said:
Is this one better...

It's 1.6 (I can't see the difference between 1.6 and 1.7)
But it's $1500 cheaper so I could get a nicer setting too.

It's E VS2 strong Fluoro
60.9 depth
56 table
33.5/41 CA/PA
50 / 80 lower girdle
Medium girdle all the way around
7.56x7.58x4.61
Without a reflector image, at least, I wouldn't commit to 41 degree PA. More on that below. And, echoing prior advice, the lower crown height could result in less perceived fire depending on particulars.

Thoughts?? Color is better, clarity is "worse", measurements are entirely different.
"Better/Worse" are not descriptors I'd use. A D Flawless diamond with nominal cut quality can be blown away by a J SI2 cut for top performance. Ok I know, it's just semantics...but you invoked the word "perfectionist" which is a trigger for me ;-)

Cut quality is going to be the key in leaving her breathless. Cut impacts size-appearance. It also impacts color, btw...color is judged face-down at the lab, with the grader looking through the pavilion. In top-cut diamonds where the critical angle for optimum light return was purposely crafted around the entire index, light entering the crown is directed immediately back out. Since it does not 'bounce around' within the diamond it doesn't illuminate the body-color like it did when the diamond was being graded upside-down. Resultantly, less color is seen face-up than the grade which was assigned at the lab. You'll find enthusiasts here who purchased top-cut I-J colors which appear more like G-H face-up. I personally wear a near-colorless diamond that blows away other pros when they see it. They regularly guess two or three color grades higher than its lab grade.

Clarity is easy in-person but harder long-distance. The most popular question: Is it eye-clean? GIA VS2 should be, but a lower price - relative to other options offered in the same channel - may imply an outlier with visible characteristics. Ultimately this judgment can only be made by someone with the diamond in-hand, using the same "eye-clean" definition as you are.

qui499kyl said:
It's actually 1.59, sorry. Rounded to 1.6
? Wait a minute. No lab rounds carat weight. Did you round it? =)

qui499kyl said:
I've never been so perfectionistic about anything before in my life. It's crazy. Anyway, thank you all and merry Christmas / happy holidays!!
I understand completely. Practically speaking, weight/spread, color and clarity questions can be answered/predicted with pretty good accuracy as long as the diamond was reputably graded.

With cut it's different. There are blind areas we cannot possibly answer, especially with GIA Reports because of the rounded and averaged data. Consider that there are 57 facets on a diamond. Every one of them is a separate measurement, and every one of them is a reflective mirror aimed...somewhere. The single number for "Crown Angle" (example) is a stand-in for 8 separate measurements, and the true average gets rounded to the nearest half-degree. So "33.5" means the average is somewhere between 33.3-33.7. What is it really? We don't know, and more importantly, we don't know how far the eight measurements behind the actual average stray. It's this way for CA, PA, Lower Halves and Stars.

PA is rounded to nearest 0.2. But this is the most important number on the report. PA given as "41.0" might be 40.9 or it might be 41.1. Now if the eight actual measurements are 40.8, 40.8, 40.8, 40.9, 40.9, 41.0, 41.0, 41.1 (true average 40.9) it's a far different story than something like 40.6, 40.8, 40.9, 41.1, 41.2, 41.2, 41.5, 41.6 (true average 41.1). That second set of numbers swings notably from the average, breaking-up internal reflections, and many individual measurements cross the sensitive 41+ threshold; so light may be windowing through the pavilion, not returning to the eye. Yet both of those number-sets would be reported as 41.0.

It's why reflector images like ASET or Ideal-Scope are posted for diamonds by cut-focused sellers. Even those do not reveal everything, but they reveal far more information than some cursory averages on a grading report.

Merry and Happy to you too, by the way.
 

John P

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diamondseeker2006|1451059875|3966121 said:
qui499kyl|1451059537|3966119 said:
Thank you! Ok, for some reason I thought 80 was better than 75, but I guess not. I read it makes the diamond more sparkly or brilliant but I guess it depends on the rest of the stone

That is just absolutely not true. Many of us have sought out old european cutting because the lower facets are even larger than 75!!! But 75 is still tiny when you look at the diamond. Did you see my picture of my diamond with 75 lgf??? It is a gorgeous stone and so much prettier than one with splinter size facets! Bigger flashes of light!!! (but still tiny when actually looking at a 7.6mm stone!)
Agree. There is no drawback to lower halves at 75% in near-Tolkowsky makes.

Prior discussion and graphics here, which may provide more perspective in the 75/80 dialogue.
https://www.pricescope.com/communit...e-up-performance.87181/#post-1373899#p1373899

One disclaimer: The graphics in that thread are modeled with "perfect" wire-frames. When considering actual diamonds always see their actual images.
 
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