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Thoughts on this stone from GOG?

LittleRiver

Shiny_Rock
Joined
Jul 25, 2011
Messages
314
Thanks to nfowife, who pointed out that GOG carries Canadian diamonds, we are now looking at this stone:

1.06 F SI1 GIA Ex/Ex/Ex HCA = 0.8
6.55 mm x 6.58 mm x 4.02 mm
Table 56.18%
Depth 61.4%
Crown Ang 35.02 deg
Pav Ang 40.58 deg
Price $8,162

Link to images: http://www.goodoldgold.com/diamond/8468/

Should I be worried about the HCA score of 0.8? I have read here that score should fall between 1 - 2. We reserved this stone and have an appointment to see it on Thursday, but I'm not sure I trust my eyes! Any others we should ask to see? This one is stretching our original budget of $7,500 a bit, but is doable. I am okay going under the magic carat mark to save money, but would prefer to stay in the colorless range.

Thanks in advance!!
 

minmin001

Ideal_Rock
Joined
Mar 21, 2011
Messages
2,047
0.8 is better than 1 :bigsmile: it looks good. also ask if there is any PS discount~
 

mogster

Shiny_Rock
Joined
Jul 7, 2011
Messages
364
I think it needs to score under 2 (not just between 1-2). The stone looks beeeautiful!
 

thbmok

Brilliant_Rock
Joined
Jul 30, 2010
Messages
891
Please trust your eyes. The HCA only gives a very rough outline. Images are a step up from the HCA and videos are even better, but nothing beats examining and comparing the stones in person.

Since you'll be visiting GOG, I suggest seeing everything around 1 ct in your price range, such as these:

http://www.goodoldgold.com/diamond/8336/
http://www.goodoldgold.com/diamond/8378/
http://www.goodoldgold.com/diamond/8379/
http://www.goodoldgold.com/diamond/8388/
http://www.goodoldgold.com/diamond/8390/
http://www.goodoldgold.com/diamond/8341/

I suggest seeing well cut stones outside the colorless range as well as it's possible that you may find them just as, or perhaps even more, attractive in person. My fiancee was certainly surprised when she found out that she actually prefers well cut stones in the H/I range over other colors.

Enjoy your trip to GOG!
 

John P

Ideal_Rock
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May 1, 2008
Messages
3,563
LittleRiver|1312296208|2982278 said:
Should I be worried about the HCA score of 0.8? I have read here that score should fall between 1 - 2.
Not true. The HCA is a rejection tool. Even its developer says it's not to be used for selection or to attempt to "break ties" below 2.0.

Basically the HCA draws a "chalk outline" of a diamond based on three important data points. If that outline indicates potentially reduced performance the score is > 2.0. If that outline is in the wheelhouse of more solid performance the score is < 2.0. No score from 0.0-2.0 is "better" than another and there are so many other variables to take into account that it cannot be used to "select" between diamonds with scores in the 0.0-2.0 range.

A grading report provides more data points than the HCA but still doesn't tell the whole story... In the case of main crown, pavilion and stars each number on a grading report is an average of eight different measurements. For the lower halves the single number represents 16 different measurements. The 16 upper girdle facets are addressed nowhere on the report at all, and though the labs scrutinize for brillianteering issues those facets are otherwise ignored.

So HCA < Grading Report < IS/ASET and while they can help narrow the field of candidates an in-person evaluation is required to understand all of the performance details, including details of cutting precision. To that end, you're working with a very cut-focused seller who is committed to exploring every facet and how all of them work together. Enjoy the process.
 

LittleRiver

Shiny_Rock
Joined
Jul 25, 2011
Messages
314
Thanks to all who replied, especially John Pollard for the helpful explanation. I will post an update after our trip to GOG.
 

nfowife

Brilliant_Rock
Joined
Mar 15, 2011
Messages
544
So glad you are going to be be able to see stones in person. I wholeheartedly agree with thmbok- I think you should look at the other stones in your size range that are Canadian. You might be surprised at what you perceive as the lower colors- how colorless they are. And that could get you quite a bit lower on budget. Have Jon do a blind test with you and see if you can tell the difference without knowing which is which- then you will know you are choosing the best stone for you, with your own eyes, knowing they are all great on paper because GOG sells top performing stones.
Best of luck!
 

John P

Ideal_Rock
Trade
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May 1, 2008
Messages
3,563
LittleRiver|1312320675|2982575 said:
Thanks to all who replied, especially John Pollard for the helpful explanation. I will post an update after our trip to GOG.
You're welcome. Looking forward to the update.
 

Rhino

Ideal_Rock
Trade
Joined
Mar 28, 2001
Messages
6,275
There is this initial statement that has always bothered me about the HCA John and in particular with the commentary most popularly given. Namely that "The HCA is a rejection tool".

When I think of the hundreds of extradinarily beautiful H&A diamonds I would have passed up if I would have taken this counsel ... particularly those that took or take the hit because of the 41.0 threshold on the pavilion angle. It's such a non issue it is perhaps one of the most tiring emails we have to answer when we'll show a person a perfectly beautiful H&A diamond with no blatant light leakage and I have to sit and explain why the diamond gets a score over 2.0. :nono: And then there are those diamonds it would reward with scores under 2.0 that suffered miserably in contrast. :sick: I think when you have the empiracle evidence of a solid Dxray photograph or properly taken IS or FireScope image the HCA needs to be pushed to the side unless the images are really suspect.
 

John P

Ideal_Rock
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You're a special case though, Rhino. The world's supply of diamonds landing above the 2.0 borderline don't all have the cut consistency, precision and minor-facet combinations you insist on to guarantee performance, unless you're blindly accepting anything now, and I know you're not; you're hand selecting your stock. So if someone's chosen jeweler in Peoria isn't as cut-focused as you (remembering that many dealers go no father in cut than a lab grade) the online HCA may be one of the only outside litmus tests that person can refer-to regarding a potential diamond purchase.

Rhino|1312382614|2983077 said:
perhaps one of the most tiring emails we have to answer when we'll show a person a perfectly beautiful H&A diamond with no blatant light leakage and I have to sit and explain why the diamond gets a score over 2.0.
I hear you. Several years ago it was the same with "painting." That description (just like HCA>2.0) earned regular caution flags on PS, and it was necessary to explain how not all diamonds with that label, especially at the threshold, deserve to fall under that flag.

In a completely different category, caution flags also exist on the SI2 and I1 grades. But I have seen diamonds in those categories which are exquisite and appear no-different to the naked eye than grades universally considered "safe." As with many things, it's a case by case basis.
 

Dancing Fire

Super_Ideal_Rock
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Apr 3, 2004
Messages
32,399
that is a beautiful stone.. :love: ask Jon if it is eye clean.
 

yssie

Super_Ideal_Rock
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Aug 14, 2009
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21,096
John Pollard|1312386102|2983130 said:
You're a special case though, Rhino. The world's supply of diamonds landing above the 2.0 borderline don't all have the cut consistency, precision and minor-facet combinations you insist on to guarantee performance, unless you're blindly accepting anything now, and I know you're not; you're hand selecting your stock. So if someone's chosen jeweler in Peoria isn't as cut-focused as you (remembering that many dealers go no father in cut than a lab grade) the online HCA may be one of the only outside litmus tests that person can refer-to regarding a potential diamond purchase.

Rhino|1312382614|2983077 said:
perhaps one of the most tiring emails we have to answer when we'll show a person a perfectly beautiful H&A diamond with no blatant light leakage and I have to sit and explain why the diamond gets a score over 2.0.
I hear you. Several years ago it was the same with "painting." That description (just like HCA>2.0)earned regular caution flags on PS, and it was necessary to explain how not all diamonds with that label, especially at the threshold, deserve to fall under that flag.

In a completely different category, caution flags also exist on the SI2 and I1 grades. But I have seen diamonds in those categories which are exquisite and appear no-different to the naked eye than grades universally considered "safe." As with many things, it's a case by case basis.


I don't suppose my input is desired... but I submit Rhino that if those people had posted their concerns here on PS where they presumably ingested only half the story to begin with instead of emailing you they'd have been set straight in two minutes. Maybe five, if particularly dogged in their skepticism. As with painting.

And if PS is indeed such a hub of activity wrt new purchases - I rather suspect there will be an influx of "but it's only 1B!" emails soon, too. Call it cynicism.


LittleRiver - that is an awfully pretty stone :sun:
 

Rhino

Ideal_Rock
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Messages
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LOL Yssie. Yes we get those too but not enough to warrant a new article yet though discussing the pros and cons of the AGA system. :read:

DF ... want to trade in your diamond? :bigsmile:
 

Dancing Fire

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Rhino|1312405196|2983395 said:
LOL Yssie. Yes we get those too but not enough to warrant a new article yet though discussing the pros and cons of the AGA system. :read:

DF ... want to trade in your diamond? :bigsmile:
no Jon,but if you got couple of 3+ ct H&A stones for sale at 2004 price please feel free to give me a call... :bigsmile:
 

Rhino

Ideal_Rock
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Dancing Fire|1312410965|2983492 said:
Rhino|1312405196|2983395 said:
LOL Yssie. Yes we get those too but not enough to warrant a new article yet though discussing the pros and cons of the AGA system. :read:

DF ... want to trade in your diamond? :bigsmile:
no Jon,but if you got couple of 3+ ct H&A stones for sale at 2004 price please feel free to give me a call... :bigsmile:

:wacko: :rodent: :tongue:

not that you would but even if you ever did my counsel would be to consign it to us first. ;))
 

Dancing Fire

Super_Ideal_Rock
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Messages
32,399
Rhino|1312411089|2983493 said:
Dancing Fire|1312410965|2983492 said:
Rhino|1312405196|2983395 said:
LOL Yssie. Yes we get those too but not enough to warrant a new article yet though discussing the pros and cons of the AGA system. :read:

DF ... want to trade in your diamond? :bigsmile:
no Jon,but if you got couple of 3+ ct H&A stones for sale at 2004 price please feel free to give me a call... :bigsmile:

:wacko: :rodent: :tongue:

not that you would but even if you ever did my counsel would be to consign it to us first. ;))
i'll keep that in mind.. ;))
 

Amys Bling

Super_Ideal_Rock
Joined
Jun 25, 2010
Messages
11,025
minmin001|1312298205|2982292 said:
0.8 is better than 1 :bigsmile: it looks good. also ask if there is any PS discount~

keep in mind all scores less than 2.0 are essentially created equal. Lower doesn'tnecessarily mean better. A .05, 1.0, 1.8 are all within the range. The HCA tool is used to reject stones that are over a specific number, not to tell us that lower is better when the scores are under 2.0. I made the same assumption initally. :))
 

LittleRiver

Shiny_Rock
Joined
Jul 25, 2011
Messages
314
Update:

:bigsmile:

The stone is stunningly, breathtakingly beautiful in person :love:

I had a silly grin on my face the whole time we were at GOG because I was having so much fun. Sarah spent over an hour and a half with us, playing with stones and the tools they use to evaluate them. The first thing we did was a blind test of five stones graded F-G-H-I-J in various conditions -- from the side in a white tray under diffuse light in the diamond dock, face up under diffuse light, and face up under spot lighting. I could easily pick out the F and the J although I could not see the difference between the G-H-I stones (I guessed incorrectly, but I can't remember which way). My SO could not see the color difference between any of the stones until I pointed it out! Then we looked at the F under the loupe to find the inclusions. They were easy to see under the loupe, but didn't bother me because I couldn't see them with my eyes. We also viewed the stone under the H&A viewer -- so neat! I had never seen a H&A stone in person, and I fell in love with the perfect, silvery arrows. We also viewed the stone under the idealscope side-by-side with a non-ideal cut stone of the same weight. Oh, and Sarah showed us the ASET....I am sure I am forgetting something! Jon stopped by to introduce himself, too.

What really struck us both was how much bigger this stone looks than other excellent (but not ideal) cut stones of the same size. It is incredibly beautiful, and I feel incredibly lucky to have it. Thanks to all who chimed in, and especially to Sarah at GOG for having fun with us.

Now the waiting begins!
 

nfowife

Brilliant_Rock
Joined
Mar 15, 2011
Messages
544
congrats!! I think you made an excellent choice and now you will not have any what ifs..... you chose the one that was best for you with your own eyes. Can't wait to see finished pictures!
 

Rhino

Ideal_Rock
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It was a pleasure to meet you Little River and Sarah expresses her gratitude.
 

kindred

Brilliant_Rock
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That sounds like so much fun! I wish I lived near GOG!
 
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