2.51 VS2 G color Round brilliant diamond opinion....

[AndyDiamond]

Hi everyone,

Just found this board, and found a potential diamond I am looking for.

It is GIA certified.

I plugged in the #'s in the HCA and it only returned fair. 60% Table, 61.7% Depth, Crown angle: 33.5 degrees, Pavillion angle: 41.8 degrees according to GIA certificate. Is that a cause for concern?

It is rated Excellent Cut, Excellent Symmetry, and Excellent Polish by GIA. Can anyone explain to me why it only returns fair by the HCA but rated triple excellent by GIA? There is a strong blue fluorescence but from what I read, there is no cause for concern, and may actually make the diamond color look one grade higher.

Please give me your opinions. What's a fair price for this diamond?

Thanks,

Andy

Full specs:

Round Brilliant
Measurements: 8.69 - 8.75 x 5.38 mm
Carat Weight: 2.51 carat
Color Grade: G
Clarity Grade: VS2
Cut Grade: Excellent
Proportions:
Depth: 61.7%
Table: 60%
Crown Angle: 33.5°
Crown Height: 13.5%
Pavilion Angle: 41.8°
Pavilion Depth: 44.5%
Star length: 50%
Lower Half: 80%
Girdle: Medium to Slightly Thick, Faceted
Culet: None
Finish:
Polish: Excellent
Symmetry: Excellent
Fluorescence: Strong Blue
Comments: Pinpoints are not shown.

 

[AndyDiamond]

BTW, the HCA score is 6.4. Is there anyway to edit a post? I was able to do it earlier, but currently the link to do it is gone. Is the ability to edit posts just time limited to a short while after posting?

Sorry for the newbie question.

Thanks,

Andy

 

[diamondseeker2006]

Yes, the edit feature just lasts for a period of time. There are better stones within GIA Excellent than others, Just glancing at the numbers, the pavilion angle is off on that stone. We usually see the best stones having a pav. angle of 40.6 to 41.0. Maybe Garry, the HCA inventor, can give you more info on the numbers on this stone.

 

[AndyDiamond]

Typo above. The score HCA score is 6.3, not 6.4 if it makes any difference.

 

[MissGotRocks]

Typo above. The score HCA score is 6.3, not 6.4 if it makes any difference.

No, as a weeding out tool, you're looking for a score of under 2.

I too would keep looking - I know the inventory of larger stones isn't plentiful but you want to find a stone that is beautifully cut and this one falls short in that regard.

 

[AndyDiamond]

Hi,

Thanks for the input. Can anyone explain how GIA rates it Excellent but actually fail the HCA test? Is a diamond that is rated just Good by GIA but a lower # on the HCA actually better? I have seen instances of HCA producing a lower score while GIA rates it lower.

If you were considering this stone, how much additional discount should be given for the problematic cut?

Andy

 

[diamondseeker2006]

Andy, honestly, there are some stones in the 2-3 range (HCA) that people consider sometimes, but I don't think I'd consider a 6 under any circumstances unless the stone was a bargain and could be recut. I'm not sure how a GIA EX could have a score that bad (and still hope Garry might see this), but I think if I were spending that much on a diamond, I would want the best cut I could find.

 

[AndyDiamond]

Diamondseeker2006,

What would you consider a bargain for a stone with these specs? It is a bit cheaper than stones with no fluorescence.

Andy

 

[diamondseeker2006]

Andy, I can only do price comparisons with online diamond listings, but there is a 2.52 ct. G VS2 listed at $38k (James Allen), but it has no fluoro, so your stone should be less than that. I'd want it priced around the same as a 2 ct. stone because I'd probably try to have it recut. Maybe you have found a second hand stone at a bargain price, and that would be terrific! If so, then we'll tell you more about recutting.

 

[AndyDiamond]

Diamondseeker2006,

The diamond I am looking at is priced around 29k, so it seems like a good price. Looking at the James Allen site, I see 2 carats with the same specs priced from around 30-34k. What's strange is that I see a 2.01 carat with faint fluorescence priced more at 34k at http://www.jamesallen.com/diamonds/G-VS2-Ideal-Cut-Round-Diamond-1418502.asp vs. a 2.05 carat one priced at around 30k with no fluorescence at http://www.jamesallen.com/diamonds/G-VS2-Ideal-Cut-Round-Diamond-1431591.asp.. Both are GIA certified.

Can you explain why the bigger, and supposedly better spec diamond cost less from the same online seller?

Andy

 

[MissGotRocks]

James Allen could explain those discrepancies better to you than we could. It could be a matter of when the stones came on the market - prices have increased very frequently. The second stone has no specs listed and the GIA cert is not available for viewing so there is really no way for us to choose one over the other. Flourescence makes a difference but it's not the only deciding factor in a stone's price.

Have you been out to a local jeweler to see an ideal cut stone? Jared's has their Peerless Line which includes AGS0 graded stones. Once you've seen a really well cut stone, I think you'd be more inclined to have one. It might mean that you'd have to drop your size parameter a bit but a smaller, well cut stone is generally more desirable than a larger so so cut stone.

Check out Brian Gavin Diamonds(they also have a line of fluro stones called BGD Blue), Whiteflash, Good Old Gold, and ID Jewelry as other sources for stones. Call any one of these vendors; they'd be happy to discuss their stones with you as would James Allen.

Good luck in your search - it can be difficult and frustrating at times but when you finally fine the perfect stone, you'll be happy that you put in the time.

If you find something else to consider, post it here and ask for thoughts!

Here is a super ideal cut stone from Whiteflash - smaller, lower color and clarity but a stunningly beautiful stone - just something to use for comparison sake - http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2696792.htm

 

[diamondseeker2006]

I think diamonds come from different sources at different times aside from differences in the specs of the stones. I think $29k is good but I'd spend the $1000 or so to send it to Brian Gavin to see if they can improve the cut. As long as it stays above 2 cts., you'll come out ahead. You might want to call them before purchasing this diamond to ask if they think the measurements sound promising for a recut or at least some tweaking.

 

[DiamondsDiamonds]

Diamondseeker's initial analysis was excellent: The pavilion angle is way off. With a 40.8 PA, for example, the HCA would be 1.8.

Forget about this diamond. The HCA is off-the-charts bad.

With respect to gradings, scores, and the like, different criteria are used by different labs/tools to determine quality, therefore the more proven tools you can utilize in addition to the GIA or AGS grading the better. It is indeed necessary to view the totality (including HCA) to get the full picture. A GIA report alone does not suffice.

 

[diamondseeker2006]

Diamondseeker's initial analysis was excellent: The pavilion angle is way off. With a 40.8 PA, for example, the HCA would be 1.8.

Forget about this diamond. The HCA is off-the-charts bad.

With respect to gradings, scores, and the like, different criteria are used by different labs/tools to determine quality, therefore the more proven tools you can utilize in addition to the GIA or AGS grading the better. It is indeed necessary to view the totality (including HCA) to get the full picture. A GIA report alone does not suffice.

Would a pavilion like that be able to be recut to improve it? The price he was quoted was less than 2 ct. excellent cut stones, so if he could have it recut and retain weight above 2 cts., he might come out ahead.

But I absolutely wouldn't buy it to use as is.

 

[AndyDiamond]

Hi Guys,

Thanks for all your help. I think I may have found a better alternative. Slightly smaller at 2.39 carats and priced at $700 more with medium blue fluorescence. It gets an HCA score of 1.6. Is the thin girdle a problem? Or twinning wisps or surface graining? Thoughts on this stone? Fair price for about $29,500?


Round Brilliant
Measurements: 8.62 - 8.65 x 5.27 mm
Carat Weight: 2.39 carat
Color Grade: G
Clarity Grade: VS2
Cut Grade: Excellent
Proportions:
Depth: 61.0%
Table: 57%
Crown Angle: 35.0°
Crown Height: 15.0%
Pavilion Angle: 40.8°
Pavilion Depth: 43.0%
Star Length: 50%
Lower Half: 75%
Girdle: Thin to Medium, Faceted (3.0%)
Culet: None
Finish:
Polish: Excellent
Symmetry: Excellent
Fluorescence: Medium Blue
Comments:
Additional twinning wisps are not shown. Surface graining is not shown.

 

[yssie]

Hi Guys,

Thanks for all your help. I think I may have found a better alternative. Slightly smaller at 2.39 carats and priced at $700 more with medium blue fluorescence. It gets an HCA score of 1.6. Is the thin girdle a problem? Or twinning wisps or surface graining?


Round Brilliant
Measurements: 8.62 - 8.65 x 5.27 mm
Carat Weight: 2.39 carat
Color Grade: G
Clarity Grade: VS2
Cut Grade: Excellent
Proportions:
Depth: 61.0%
Table: 57%
Crown Angle: 35.0°
Crown Height: 15.0%
Pavilion Angle: 40.8°
Pavilion Depth: 43.0%
Star Length: 50%
Lower Half: 75%
Girdle: Thin to Medium, Faceted (3.0%)
Culet: None
Finish:
Polish: Excellent
Symmetry: Excellent
Fluorescence: Medium Blue
Comments:
Additional twinning wisps are not shown. Surface graining is not shown.

The basics - http://www.gia.edu/diamondcut/pdf/culet_girdle_assessment_0106.pdf
No, esp in a stone of this size - girdle ranges represent percentages of diametre, so 1% of a 5mm diametre stone is obviously a lot less in mm than 1% of 8.5mm. And it's a reputably graded VS2 so inclusions should not be considered durability risks or visibly impact light return.

 

[MissGotRocks]

I like this stone a lot better than the first one - you may be on to something now!

 

[AndyDiamond]

Hi guys,

I talked to the seller and he thinks the HCA data is outdated, and GIA is using newer data to rate it as triple excellent so there is nothing to worry about. Any truth to that? He claims the diamond will sparkle just as much to the naked eye, and the minute differences are just detectable by a machine. He thinks the 2.51 carat diamond is a better value than the 2.39. I requested an Idealscope image to verify, so waiting for that.

 

[diamondseeker2006]

I'd be putting my money on the smaller stone without a doubt! It is MUCH better! And in fact, it's diameter is near the size of the other one anyway. It really will not appear hardly any smaller.

 

[sillysweetie]

A PSer Phoenix is selling her 2.6ct H&A diamond (not sure if it's sold yet) and here's the link to it: [URL='https://www.pricescope.com/forum/preloved-ps-jewels/2-656ct-h-si2-bgd-signature-h-a-diamond-pendant-t166074.html']https://www.pricescope.com/forum/preloved-ps-jewels/2-656ct-h-si2-bgd-signature-h-a-diamond-pendant-t166074.html..[/URL]. It seems to be what you're looking for.

 

[TimMD]

Hi guys,

I talked to the seller and he thinks the HCA data is outdated, and GIA is using newer data to rate it as triple excellent so there is nothing to worry about. Any truth to that? He claims the diamond will sparkle just as much to the naked eye, and the minute differences are just detectable by a machine. He thinks the 2.51 carat diamond is a better value than the 2.39. I requested an Idealscope image to verify, so waiting for that.

To me this sounds like the line of a salesman but that is just my opinion. I am with DS and the rest of the posters with I think the 2.39 sounds like a much better stone but if you have the chance to see them side by side, let your eye see for itself.

 

[AndyDiamond]

A PSer Phoenix is selling her 2.6ct H&A diamond (not sure if it's sold yet) and here's the link to it: [URL='https://www.pricescope.com/forum/preloved-ps-jewels/2-656ct-h-si2-bgd-signature-h-a-diamond-pendant-t166074.html..']https://www.pricescope.com/forum/preloved-ps-jewels/2-656ct-h-si2-bgd-signature-h-a-diamond-pendant-t166074.html....[/URL]. It seems to be what you're looking for.

I am looking for a higher color and clarity.

 

[Garry H (Cut Nut)]

Hi guys,

I talked to the seller and he thinks the HCA data is outdated, and GIA is using newer data to rate it as triple excellent so there is nothing to worry about. Any truth to that? He claims the diamond will sparkle just as much to the naked eye, and the minute differences are just detectable by a machine. He thinks the 2.51 carat diamond is a better value than the 2.39. I requested an Idealscope image to verify, so waiting for that.

I doubt anyone will send you an Ideal-scope image for the 41.8 pav stone. It would be the kiss of death.
http://www.octonus.ru/oct/mss/gia&agspgs.phtml shows the stone is just inside the GIA border line and would be expected to be AGS3 if the symmetry was perfect.
Naturally the stones in the center of the 56-57% table size range are the best, and this is a proportion set that GIA only just allowed in Ex. There is plenty of evidence that GIA was swayed by trade opinions. The opinions and the lighting used favoured deeper higher yielding stones.

 

[AndyDiamond]

Garry,

Thanks for the insight. Besides Ideal-scope images, should I have ask for anything else? Is Gem Advisor any better?

 

[AndyDiamond]

Any other opinions? What about ASET? Basically, what's the best to ask for to verify the diamond before purchase?

Thanks.

 

[Rockdiamond]

Hi guys,

I talked to the seller and he thinks the HCA data is outdated, and GIA is using newer data to rate it as triple excellent so there is nothing to worry about. Any truth to that? He claims the diamond will sparkle just as much to the naked eye, and the minute differences are just detectable by a machine. He thinks the 2.51 carat diamond is a better value than the 2.39. I requested an Idealscope image to verify, so waiting for that.

To me this sounds like the line of a salesman but that is just my opinion. I am with DS and the rest of the posters with I think the 2.39 sounds like a much better stone but if you have the chance to see them side by side, let your eye see for itself.

Outdated implies HCA was , at one point, widely accepted- and that's just not the case.

Andy- there's a lot of differing opinions on this.
I'd be interested to see the evidence Garry mentions about the trade swaying GIA ( never works when I try

I have consistently found that I love GIA EX cut grade stones that HCA knocks.
I'm not suggesting you buy the first stone- or that you don't- but understanding how HCA relates to a retail purchase- and what is salesman's BS, is VERY important for shoppers reading this forum.
Ain't Nobody discount GIA EX cut grade diamonds because they flunked HCA tests.

 

[Garry H (Cut Nut)]

Why buy an outlyer on the border of a lower quality when there are other stones that everyone agrees is a better proportion set?
The same would apply for color and clarity.
David you really could consider this when you continually advise people to buy steeper deeper stones.

 

[Marisa_Perry]

Dear Andy,
Diamonds and engagement rings are my profession and I wanted to lend my opinion. I agree with your first post that strong blue fluorescents are not necessarily a negative, they can indeed make the stone look whiter, but once in a while they can make the stone look milky. That is what you do not want and the only way to tell, is to see it. It it looks sparkly and reflects light, it is a keeper at the right price. If it looks opaque or milky, ditch it and go for others. Certs and lab tests are not substitute for the naked eye! If you are buying such an expensive stone, please see it first and compare it to others in its category. And there is a significant price increase over a 2.5 as under so the first diamond could well be a better purchase. Is it possible for you to see them side by side, with a couple of other cushions with no fluorescents to compare?