GCAL vs AGL - can i see H&A?

[sleeprequired]

ok so after doing a lot of research i want to know what i'd be missing if i thought i could tell what i needed to from the GCAL report..

seems like an H&A cut to me....

http://www.bluenile.com/certs/221350038.pdf?params=cHJvZHVjdD1CTiZwaG9uZT0xKzgwMCs0MjUrMDIyJmxpbms9aHR0cCUzQSUyRiUyRmF1LmJsdWVuaWxlLmNvbSUyRiUyRl9MRDAyNTY5OTQzJnNrdT1MRDAyNTY5OTQzJmxhYj1nY2FsJnNpemU9MTYwMCZjdXJyZW5jeT1BVUQm

great price too for a GIA E at 13.7 k....

Light return great, good hearts and arrows pattern with some splitting of the hearts ....

what could i be missing?

 

[denverappraiser]

Hi Sleep,

As far as I know, GCAL doesn't grade hearts and arrows and nothing about it is on that report (Not that this means it isn't, it's just not documented or claimed on this report). Who is AGL? How are you deciding this is a h&a? Against what are you comparing it?

 

[sleeprequired]

Typo. Ags. If a mod could change it that would be great.

What I'm saying is what do you think? Crown angles are right, pavilion right, lower girdles are right, stars, symmetry.

You can clearly see those hearts and they're pretty good from what I can see...

Be interesting to see what everyone thinks you can tell. I'm aware of the official differences.

 

[denverappraiser]

Typo. Ags. If a mod could change it that would be great.

What I'm saying is what do you think? Crown angles are right, pavilion right, lower girdles are right, stars, symmetry.

You can clearly see those hearts and they're pretty good from what I can see...

Be interesting to see what everyone thinks you can tell. I'm aware of the official differences.

It's not a matter of official differences. The darkfield pavilion view is not a valid way to assess hearts so we just don't have enough info to work from.

AGS doesn't evaluate h&a either.

I'm not trying to nitpick here. You asked about H&A, and it's important to understand the terms. Blue Nile isn't claiming it, GCAL isn't using it, neither company has provided the raw images for a 3rd party to evaluate. There's not even info enough to model it (star and lower girdle are missing on the GCAL and GIA rounds to the point that it's useless for this purpose). AGS isn't involved at all and they have no h&a scale even if they were so I'm not seeing the GCAL vs. AGS comparison you're asking about.

Is it a lovely stone? Probably. GIA/xxx spans a pretty broad range but it's a nice place to start and are nearly all are nice looking stones. Does it display hearts and arrows symmetry? I haven't a clue. The data simply isn't there no matter what definition you want to use. If it's an important attribute to you, have it evaluated by someone who can see the stone in person and who is prepared to assign a grade as a contingency of your purchase. BN has an agreeable return policy so you should have ample time to do whatever tests you like.

 

[TitanCi]

Is it safe to assume most well/ideal cut diamonds exhibit "hearts" and "arrows" to a certain degree without it being called a true H&A stone?

 

[denverappraiser]

Is it safe to assume most well/ideal cut diamonds exhibit "hearts" and "arrows" to a certain degree without it being called a true H&A stone?

No.

H&A is a pattern in the symmetry that requires, among other things, perfect alignment between the pavilion and crown facets and a specific relationship between the individual pavilion main angles and the lower girdle length on the opposing side. 'GIA-Excellent' has limits on this but the ranges are way beyond what anyone could legitimately call hearts and arrows, even with a very unusual set of rules. It's actually possible to get some of the best hearts by cutting the stone outside of GIAx by careful treatment of the outside row of facets. This is called brillianteering and some like it while others don't. There is not a well defined standard for what is a valid h&a vs. some near-hearts kind of pattern so whenever is using these terms it's terribly important to understand what they are intended to mean. This is especially true of dealers who are using the claim to defend a particular price point. In the case here, neither the dealer or the lab is making any sort of claim at all so there's nothing for them to defend.

Here's a tidbit of diamond history: Eightstar was one of the early successful players in the h&a game. They developed a style of cutting and a look that really made the hearts pop in the viewer and it built them a nice specialty market. When GIA came out with their cut grade in 2006, their 'excellent' category excluded the vast majority of Eightstars because of exactly what they were doing that made them different/special. They're still as lovely as they ever were and they're still among the finest 'hearts and arrows' diamonds ever cut, but all of a sudden they were saddled with the label of 'very good' or sometimes even 'good' cut grades from 'the worlds foremost authority'. To say the least this was disasterous to the company and they still haven't recovered.

 

[sleeprequired]

Is it a lovely stone? Probably. GIA/xxx spans a pretty broad range but it's a nice place to start and are nearly all are nice looking stones. Does it display hearts and arrows symmetry? I haven't a clue. The data simply isn't there no matter what definition you want to use. If it's an important attribute to you, have it evaluated by someone who can see the stone in person and who is prepared to assign a grade as a contingency of your purchase. BN has an agreeable return policy so you should have ample time to do whatever tests you like.

Does this help? http://au.bluenile.com/diamond-search?track=head#diamonds_pid=LD02569943

that gives you the stars and the lower girdles. Judging by the thickness of where the bottom point of the heart meets the arrow, after looking at a bazillion hearts images I think you can pretty much say that's in line with what you see in a lot of hearts images, sure the thickness changes depending on the lower girdle number... but the certificate says 80. Now i know GIA leaves room for variation so when you look up the hearts image you get online at say - http://heartsandarrows.com/hearts-arrows-diamond-ideal-cut-dna.aspx,,, it certainly tells you that it's, for all intents and puposes, bang on.

Star facets - the certificate says 50, and the pattern in the image seems to suggest it would be a bit higher than that and also the pavilion angle steeper to create what we see in the top crown.

So with GIA, i *think* i read 0.2% variation from what's on the certificate yeah for percentages, so it looks to me like we have a genuine hearts & arrows cut without Blue Nile officially calling it that? The only thing i *think* i can tell is that the hearts seem to have some slight splits, but then so do a lot of others that are hearts & arrows....

** Disclaimer**

Sorry I just wanted to add this is purely a conversation regarding what the naked eye can tell, i'm not trying to label the stone an official H&A or anything like that...

just in case....

 

[denverappraiser]

It’s certainly possible that this stone will display reasonable h&a symmetry. The data from the GIA and GCAL reports, which is all you have to work with, is not sufficient to tell. You've asked several times about what can be seen but no one who has actually seen the stone either with the naked eye or using tools is claiming it. Wishing there were more data present doesn't really change this. Is it an important issue to you?

GIA is measuring with Sarin equipment and +/- 0.2 is the stated margin of callibration from Sarin. They then round the Sarin results to their ranges. In the case of LGF's, this is 75 - 80 - 85%. This means with no errors a stated result of 80 on a GIA report means somewhere between 75.5 - 84.5.

FWIW, in most cases diamonds end up mounted in a piece of jewelery solidly set in the faceup position. This means that the 'hearts' aren't visible with the naked eye after setting anyway.

 

[sleeprequired]

Wow, rounding to the nearest 5%. In that case professional eye would definitely be capable of gleaming more accurate information than the certificate says from those images.

5%. Again wow.

 

[nkc]

http://www.bluenile.com/signature-ideal-round-diamonds

 

[Karl_K]

You can flip a diamond over on a counter and use a toilet paper tube to see hearts also but its not accurate enough to verify h&a.
The pics are not as clear as using the toilet paper tube by a factor of about 3.

 

[nkc]

I was not refering to the picture.

There's a statement on Blue Nile Website (the link I sent earlier) saying all Blue Nile signature diamonds are H&A.

 

[diamondseeker2006]

Unless they show the pictures proving it, the words mean nothing.

 

[nkc]

Why would a big company post a false statement?

If the statement means nothing, why would the picture be true and not for another diamond?

 

[diamondseeker2006]

Why would a big company post a false statement?

If the statement means nothing, why would the picture be true and not for another diamond?

I just answered this on the other thread, but here it is....

Because they can define "hearts and arrows" any way they want. It doesn't mean the standards are the same as they are for WhiteFlash A Cut Above, Crafted by Infinity, Good Old Gold Signature Hearts and Arrows, or Brian Gavin Signature. We don't know because they don't provide the images.

 

[nkc]

I'm really curious about this.

How do I know which standard and definition is most accurate? Does the jewellers you've mentioned cut thier own diamonds? If not, what makes thier hearts and arrows more accurate?

Also, I can see perfect hearts & arrows in the GCAL. What's the difference between the H&A in thier report and the GCAL?

 

[nkc]

Diamondseeker2006,

You don't have to answer any question you don't want to answer.

My question on the other thread was about a specific diamond and is actually adressed to John Pollard.

 

[denverappraiser]

I'm really curious about this.
How do I know which standard and definition is most accurate?

You ask the person making the claim what they are using and then critically consider their answer. There is NOT a standardized set of definitions in the industry and the closest I’ve found are the ones at use at HRD, which are pretty broad. If your seller is making a claim, ask them to explain how they came to their conclusion. If you find their argument persuasive, go with it. If not, and if it’s important to you, don’t just find another stone, find another dealer.

There’s an ongoing undercurrent right here on PS over this topic. The tutorial on H&A was written by Brian Gavin when he was employed by Whiteflash and it provides his vision of what does and doesn’t make a stone h&a. Other dealers, say JamesAllen or HeartsOnFire, use different (and less publicly available) standards. Infinity uses another standard and GoG yet another. That doesn’t make one stone better than another, in fact it doesn’t even make the stones different. It means they might be different. Brian no longer works at WF and hasn’t for several years. The new guys in charge at WF can and do change the rules as they find appropriate. I think they’re basically the same as they always were but the core rule a decade ago was ‘Brian liked it’ and obviously this has now changed. If you want to know what they mean by an h&a claim, the appropriate thing is to ask THEM. Brian now works for BGD and although his grading methodology didn’t change when he moved to the new company, they too can and do tweak tiny things over time so the same applies to him. If BGD makes a h&a claim and you want to analyze exactly what it does and doesn't mean, ask THEM.

In your case the claim of h&a is coming from Blue Nile, not GCAL, not GIA, and not AGS. They have interpreted data they found on the various lab reports and possibly other sources and produced this claim. Do you believe them? Do you care? That’s up to you to decide and it seems to be the heart of your question. Is it really an h&a, is it comparable to other h&a’s that you’ve been offered and is it a better value? It may be, but that’s why this issue of standards is so important. Stone A is claimed to be h&a and it’s cheaper than an otherwise similar stone B claimed to be h&a by someone else. Is it a better value? Obviously the key to answering this sort of question revolves around analyzing the claims, not just the stones. Given that no one here can actually see either stone, that means that the ONLY thing to look at is the claim

 

[nkc]

thank you denverappraiser

 

[nkc]

I'm really curious about this.
How do I know which standard and definition is most accurate?

You ask the person making the claim what they are using and then critically consider their answer. There is NOT a standardized set of definitions in the industry and the closest I’ve found are the ones at use at HRD, which are pretty broad. If your seller is making a claim, ask them to explain how they came to their conclusion. If you find their argument persuasive, go with it. If not, and if it’s important to you, don’t just find another stone, find another dealer.

There’s an ongoing undercurrent right here on PS over this topic. The tutorial on H&A was written by Brian Gavin when he was employed by Whiteflash and it provides his vision of what does and doesn’t make a stone h&a. Other dealers, say JamesAllen or HeartsOnFire, use different (and less publicly available) standards. Infinity uses another standard and GoG yet another. That doesn’t make one stone better than another, in fact it doesn’t even make the stones different. It means they might be different. Brian no longer works at WF and hasn’t for several years. The new guys in charge at WF can and do change the rules as they find appropriate. I think they’re basically the same as they always were but the core rule a decade ago was ‘Brian liked it’ and obviously this has now changed. If you want to know what they mean by an h&a claim, the appropriate thing is to ask THEM. Brian now works for BGD and although his grading methodology didn’t change when he moved to the new company, they too can and do tweak tiny things over time so the same applies to him. If BGD makes a h&a claim and you want to analyze exactly what it does and doesn't mean, ask THEM.

In your case the claim of h&a is coming from Blue Nile, not GCAL, not GIA, and not AGS. They have interpreted data they found on the various lab reports and possibly other sources and produced this claim. Do you believe them? Do you care? That’s up to you to decide and it seems to be the heart of your question. Is it really an h&a, is it comparable to other h&a’s that you’ve been offered and is it a better value? It may be, but that’s why this issue of standards is so important. Stone A is claimed to be h&a and it’s cheaper than an otherwise similar stone B claimed to be h&a by someone else. Is it a better value? Obviously the key to answering this sort of question revolves around analyzing the claims, not just the stones. Given that no one here can actually see either stone, that means that the ONLY thing to look at is the claim

Great information Denverappraiser.

I won't be able to spend time here this week but will be back next week with more questions.

Thank you for your reply.

 

[distracts]

Why would a big company post a false statement?

Because of dumb people and money and separating the former from the latter.