Hearts and Arrows vs. Other Ideal Cuts

[mynameisnoah]

I need help understanding the difference between the ''hearts and arrows'' cut and other ideal cuts. Is it worth the price jump to go with H&As?

For example, what do you think of these two diamonds from blue nile:

http://www.bluenile.com/round-diamond-1-carat-signature-ideal-cut-g-color-vs2-clarity_LD01158185?__fun_frm=i&filter_id=0

http://www.bluenile.com/round-diamond-1-carat-signature-ideal-cut-g-color-vs2-clarity_LD01469597?__fun_frm=i&filter_id=0

Thank you!!!

 

[Lorelei]

Date: 7/13/2009 10:06:04 AM
Author:mynameisnoah
I need help understanding the difference between the 'hearts and arrows' cut and other ideal cuts. Is it worth the price jump to go with H&As?

For example, what do you think of these two diamonds from blue nile:

http://www.bluenile.com/round-diamond-1-carat-signature-ideal-cut-g-color-vs2-clarity_LD01158185?__fun_frm=i&filter_id=0

http://www.bluenile.com/round-diamond-1-carat-signature-ideal-cut-g-color-vs2-clarity_LD01469597?__fun_frm=i&filter_id=0

Thank you!!!

This page will be helpful to you as it gives a good intro to hearts and arrows.

http://diamonds.pricescope.com/hna.asp




http://www.bluenile.com/round-diamond-1-carat-signature-ideal-cut-g-color-vs2-clarity_LD01158185?__fun_frm=i&filter_id=0


http://www.bluenile.com/round-diamond-1-carat-signature-ideal-cut-g-color-vs2-clarity_LD01469597?__fun_frm=i&filter_id=0

Both of the diamonds above show promise by the numbers but thats all we can tell without images, BN do not provide them. As to whether these are h&a it is unlikely, they appear to be well cut but no way to judge overall cut precision without images.

What to pick....It depends on you. A ' true' h&a is a down to strict precision cutting, some diamonds may be called h&a and show a definite hearts and arrows pattern, yet not be cut to the standards necessary to be great examples of this cutting style, images are always essential both of the hearts and arrows in order to evaluate each diamond said to be h&a properly.

Some want only a branded h&a, the precision and pedigree, others are ok with a well cut diamond which isn't h&a, or some stones which show this patterning but are not sold as such are just fine with other buyers, so it depends on you.

BN do not to my knowledge offer their own brand of h&a, nor do they offer images. They do have good diamonds for sale but if you want a ' true' h&a then you would be best looking at the following brands and vendors.

www.briangavindiamonds.com BG Signature h&a

www.highperformancediamonds.com Infinity h&a

www.whiteflash.com A Cut Above h&a

www.goodoldgold.com hand picked h&a

www.niceice.com hand selected h&a.

 

[stone-cold11]

Date: 7/13/2009 10:11:22 AM
Author: Lorelei
BN do not to my knowledge offer their own brand of h&a, nor do they offer images. They do have good diamonds for sale but if you want a '' true'' h&a then you would be best looking at the following brands and vendors.

BN Signature Ideal is advertised as H&A. Just can''t tell from the Reports that comes with it.

 

[Lorelei]

Date: 7/13/2009 10:24:18 AM
Author: Stone-cold11

Date: 7/13/2009 10:11:22 AM
Author: Lorelei
BN do not to my knowledge offer their own brand of h&a, nor do they offer images. They do have good diamonds for sale but if you want a ' true' h&a then you would be best looking at the following brands and vendors.

BN Signature Ideal is advertised as H&A. Just can't tell from the Reports that comes with it.

Yes they may call them h&a but to me I reserve major judgement as no clear supporting images and suchlike, h&a to me is Infinity, BGSI, ACA etc.

 

[elle_chris]

The only thing I''d like to add to what''s already been said, (and said well) is not to confuse h&a''s with light return.

Ideal cut stones with great idealscope and/or aset images should perform just as well as H&A''s.

 

[stone-cold11]

Date: 7/13/2009 10:27:24 AM
Author: Lorelei

Date: 7/13/2009 10:24:18 AM
Author: Stone-cold11

Date: 7/13/2009 10:11:22 AM
Author: Lorelei
BN do not to my knowledge offer their own brand of h&a, nor do they offer images. They do have good diamonds for sale but if you want a ' true' h&a then you would be best looking at the following brands and vendors.

BN Signature Ideal is advertised as H&A. Just can't tell from the Reports that comes with it.

Yes they may call them h&a but to me I reserve major judgement as no clear supporting images and suchlike, h&a to me is Infinity, BGSI, ACA etc.

I understand, I am saying BN's Signature Ideal is their branded H&A. You said they don't offer, which is wrong. Just that there is no supporting H&A images that you like. This is similar to GOG's signature ideal, except GGO presented H&A images.

That is all I am saying.

 

[Lorelei]

Date: 7/13/2009 10:44:35 AM
Author: Stone-cold11

Date: 7/13/2009 10:27:24 AM
Author: Lorelei

Date: 7/13/2009 10:24:18 AM
Author: Stone-cold11

Date: 7/13/2009 10:11:22 AM
Author: Lorelei
BN do not to my knowledge offer their own brand of h&a, nor do they offer images. They do have good diamonds for sale but if you want a ' true' h&a then you would be best looking at the following brands and vendors.

BN Signature Ideal is advertised as H&A. Just can't tell from the Reports that comes with it.

Yes they may call them h&a but to me I reserve major judgement as no clear supporting images and suchlike, h&a to me is Infinity, BGSI, ACA etc.

I understand, I am saying BN's Signature Ideal is their branded H&A. You said they don't offer, which is wrong. Just that there is no supporting H&A images that you like. This is similar to GOG's signature ideal, except GGO presented H&A images.

That is all I am saying.

Ok I see what you are saying, they don't seem to make a big to do about advertising them as h&a ( the rounds, as we know they call other shapes SI also) to me they are really not a branded h&a as I know them to be. It isn't a case of h&a images " that I like" particularly, it is a case of them not offering distinct and clear images of the hearts and arrows that are easily readable by anyone wanting a H&A diamond. To me no clearly visible images of both hearts and arrows = no h&a.

 

[risingsun]

I think this is one of the best tutorials I've read about performance and precision and the relationship between the two. For anyone wondering about h&a diamonds, I recommend these two educational pieces:

http://www.highperformancediamonds.com/index.php?page=education-precision

 

[elle_chris]

Have their been any studies done by GIA or AGS that shows for a fact that cut precision on top light performers increases light return, scint and fire in low light conditions?

The tutorial on Infinity's site says it "can", but doesn't say it "does". I'm also wondering even if it did, would it even be detectable by the human eye.

Maybe the experts can start a thread on this?

 

[Black Jade]

I have a Blue Nile ring with an F color AGS0 diamond and I have Whiteflash H color diamond stud earrings, ACA AGS0 Hearts and Arrows. (the ring has a .65 diamond in it and the earrings have .91 in each earring, 1.81 ctw).

Both the earrings and the ring are definitely the same quality. Both are Hearts and Arrows. The Blue Nile diamond looks exactly the same as the WF diamonds do, using the whiteflash Hearts and Arrows viewer.

The Blue Nile diamond was not a Signature Ideal. What I did when I was buying it was to run the specs through the Holloway cut advisor here on the pricescope site. The numbers came out great. And then I ordered it. I knew that if I did not like it, I had a 30 day window to return it. I have returned things to Blue Nile before and its an easy, painless process.

I am not pushing Blue Nile over Whiteflash. Both vendors made me very happy. You get personal attention from Whiteflash that you do not get at Blue Nile and you get lots of photos and charts and graphs and so on that some people really like to have. Also, Whiteflash has an upgrade policy that is very important to many people who use P-scope. I loved the process of getting my earrings at Whiteflash and the earrings are beautiful. But I don''t necessarily want that much advice/help with every purchase. Also, Bluenile is cheaper. I don''t mean in the sense that the SAME thing will necessarily be cheaper at Bluenile. But Bluenile has a much wider range of products, so if you have less money to spend on a purchase, you are more likely to find something lovely but not necessarily top of the line at Bluenile. I don''t know if what I''m saying makes sense.

People have different personalities and I think the people who tend to post a lot on Pricescope and give advice tend to have the sort of personality where they are super-perfectionists and love images and charts and graphs (which CAN make you more secure about what you will get if you buy online). But I don''t think that you necessarily NEED all of that to get a beautiful diamond, and you don''t even need it to get an H & A (if you HAVE to one of those). Everytime I have got an AGS0 (which is now, 4 times) and checked it out through the Holloway cut advisor, they have been spectacular diamonds and definitely had H&A through the viewer, yet you don''t necessarily have to pay the premium for H & A.

Of course this advice is only good if you want a round, modern diamond. I would definitely go with a vendor like Whiteflash where they hold your hand a lot if you wnat some sort of a fancy diamond such as Asscher or Marquise or Emerald Cut.

 

[Lorelei]

Jade thats fine, but for those who want an undisputed h&a diamond clear and distinct images are essential when purchasing which BN do not provide to the best of my knowledge, a h&a diamond which might show strong hearts and arrows patterning can ' fail' quite easily on faults in that patterning which aren't necessarily obvious to the layman. BN do sell excellently cut diamonds but for those who want a true h&a which is cut to the strict standards necessary there is no way to tell without images, and that is the bottom line. If a buyer is happy with a diamond which is said to be h&a and aren't bothered about images then no problem at all, but personally if a buyer comes here and says yes they want a undisputed h&a diamond then the known brands are the only way to go, or a sold as h&a diamond which has the essential hearts images and also arrow images in order to substantiate this claim. Again no images = no h&a in my opinion and I know others feel the same way.

From an experienced consumer advisor's point of view, this is the only approach I can take if someone wants advice on how to buy an undisputed h&a, I cannot responsibly steer them in the direction of a so called h&a diamond which does not have clear and distinct images to prove it is. Conversely if a poster just wants a well cut stone I often steer them in another direction.

To expound on how strict the standards are for a h&a diamond, see this article if you haven't already done so.

http://journal.pricescope.com/Articles/65/1/Hearts-and-Arrows-Diamonds-and-The-Basics-of-Diamond-Cutting.aspx

 

[stone-cold11]

Date: 7/13/2009 12:10:27 PM
Author: elle_chris
Have their been any studies done by GIA or AGS that shows for a fact that cut precision on top light performers increases light return, scint and fire in low light conditions?

The tutorial on Infinity''s site says it ''can'', but doesn''t say it ''does''. I''m also wondering even if it did, would it even be detectable by the human eye.

Maybe the experts can start a thread on this?

I think Wink''s video on AGS''s Director Peter Yantzer, seems to imply they are looking into studying in that direction. H&A pattern having bigger virtual facets than non ideal symm stones.

 

[elle_chris]

Date: 7/13/2009 12:36:04 PM
Author: Stone-cold11

Date: 7/13/2009 12:10:27 PM
Author: elle_chris
Have their been any studies done by GIA or AGS that shows for a fact that cut precision on top light performers increases light return, scint and fire in low light conditions?

The tutorial on Infinity''s site says it ''can'', but doesn''t say it ''does''. I''m also wondering even if it did, would it even be detectable by the human eye.

Maybe the experts can start a thread on this?

I think Wink''s video on AGS''s Director Peter Yantzer, seems to imply they are looking into studying in that direction. H&A pattern having bigger virtual facets than non ideal symm stones.

I''m talking about ideal symmetry stones, just not H&A''s.

Jade- I''m in full agreement with you about not being able to see the difference as I can''t either between my H&A''s and just AGS Ideal and GIA excellent (but with my GIA excellent I was very careful when choosing).

But like Lorelei said, if someone comes on asking for H&A''s, it''s a safer bet to point them to a trusted vendor that specializes in these cuts so there''s no chance of them getting a dud.

The OP though asked if it''s worth the price jump. To some it is, to others it''s not. But if you''re looking for a true H&A then the vendors that Lorelei listed all have images backing up their product. Blue Nile does not (at least yet).

 

[Black Jade]

Sorry, I didn''t mean to undercut anybody''s advice or to offend.

I just don''t see where the OP says that he definitely wants an H & A. I see where he''s asking what the difference is between H & A and other diamonds and if H&A is worth the price difference.

The technical advice is all great. and it is wonderful how all of you are willing to take your time and give that. I know it has helped me a lot.

I just thought he might like the point of view of someone, not an expert admittedly, who had diamonds both from Bluenile (which he was specifically asking about) and the P''scope vendors that he got recommended to him, especially since there is IS a price difference (which is important to some people). It''s another point of view, that''s all.

 

[Lorelei]

Date: 7/13/2009 1:17:29 PM
Author: Black Jade
Sorry, I didn't mean to undercut anybody's advice or to offend.

I just don't see where the OP says that he definitely wants an H & A. I see where he's asking what the difference is between H & A and other diamonds and if H&A is worth the price difference.

The technical advice is all great. and it is wonderful how all of you are willing to take your time and give that. I know it has helped me a lot.

I just thought he might like the point of view of someone, not an expert admittedly, who had diamonds both from Bluenile (which he was specifically asking about) and the P'scope vendors that he got recommended to him, especially since there is IS a price difference (which is important to some people). It's another point of view, that's all.

You didn't and don't worry!

He didn't say he definitely wanted a h&a, he asked for info so he could understand the difference between h&a and other ideal cuts and whether the premium is worth it, so I linked a tutorial and explained the differences to him. Also I explained the ultimate choice is down to the buyer and their preferences whether to choose a h&a or not, that both BN diamonds showed promise but as to being h&a cuts no way to tell without images. Also we can't categorically state that any diamond will be an absolute winner really without an Idealscope or ASET image as there is so much info we are missing, faceting, angle variances, optical symmetry and how it all works together, so although some proportion configurations might be a fair bet that we can say ' yes this should be a good looking diamond' we can't always say for sure without images.

Bottom line for this poster as I said above, both of the diamonds he is interested in could be great stones, but as to whether they are h&a no way to tell without images, if he is happy to go for non h&a then either of these might fit the bill, if he prefers a ' true' h&a then a diamond with supporting images is the way to go. I have been taught this for years here by the experts, you cannot judge overall cut precision of any so called h&a diamond without images, particularly hearts images.


And another POV is fine Jade! If you watch a lot you will see that we try to tailor the advice according to what the poster says they want, if it is a h&a then we have vendors who specialize in these with all the supporting images, if just a well cut diamond we might go in another direction. It is not an easy path for the PS consumer advisor to walk, anyone can sign up to offer advice but the trick is to do it well and try to explain in a way which resonates with the new consumer, not everyone can do this well as it isn't easy but we do need to keep trying to improve standards all the time, not just with technical info but the way it is presented. Just because WE understand this stuff doesn't mean the new poster will so we need to strive to improve the quality of our posts and keep this place an excellent resource!

 

[Black Jade]

It''s not the clearest photo, but here''s a picture of my ACA studs with my blue nile AGS0 (but not branded H & A) in between them. I think you can see what I mean, from the photo, about the quality of both being simply superb. I repeat the stats-- earrings are H VS2 ACA AGS0 from whiteflash.com, .90 and .91 (1.81 ctw) and the ring is F, SI1, AGS0 but not branded H&A and not Signature Ideal Cut from bluenile.com, in a bluenile platinum setting. .65 carat. I got photos, ASET images and superb service from whiteflash and would recommend them to anybody, but I would also recommend Bluenile.com, depending on the person''s personality and how detailed they liked to be when the shopped.
The service at BN is also great. Perhaps the OP would just like to telephone both vendors.

 

[risingsun]

When someone comes to PS asking about whether it's worth the money to buy a h&a diamond, I feel that it is prudent to provide them with education about what a h&a diamond is. There is no pressure to purchase one, but at least there is a point of reference. There appears to be increasing research, which supports a correlation between precision and performance. I will be interested to hear more about this in the future.

 

[Black Jade]

Date: 7/13/2009 1:25:35 PM
Author: Lorelei

Date: 7/13/2009 1:17:29 PM
Author: Black Jade
Sorry, I didn''t mean to undercut anybody''s advice or to offend.

I just don''t see where the OP says that he definitely wants an H & A. I see where he''s asking what the difference is between H & A and other diamonds and if H&A is worth the price difference.

The technical advice is all great. and it is wonderful how all of you are willing to take your time and give that. I know it has helped me a lot.

I just thought he might like the point of view of someone, not an expert admittedly, who had diamonds both from Bluenile (which he was specifically asking about) and the P''scope vendors that he got recommended to him, especially since there is IS a price difference (which is important to some people). It''s another point of view, that''s all.

You didn''t and don''t worry!

He didn''t say he definitely wanted a h&a, he asked for info so he could understand the difference between h&a and other ideal cuts and whether the premium is worth it, so I linked a tutorial and explained the differences to him. Also I explained the ultimate choice is down to the buyer and their preferences whether to choose a h&a or not, that both BN diamonds showed promise but as to being h&a cuts no way to tell without images. Also we can''t categorically state that any diamond will be an absolute winner really without an Idealscope or ASET image as there is so much info we are missing, faceting, angle variances, optical symmetry and how it all works together, so although some proportion configurations might be a fair bet that we can say '' yes this should be a good looking diamond'' we can''t always say for sure without images.

Bottom line for this poster as I said above, both of the diamonds he is interested in could be great stones, but as to whether they are h&a no way to tell without images, if he is happy to go for non h&a then either of these might fit the bill, if he prefers a '' true'' h&a then a diamond with supporting images is the way to go.


And another POV is fine, if you watch a lot you will see that we try to tailor the advice according to what the poster says they want, if it is a h&a then we have vendors who specialize in these with all the supporting images, if just a well cut diamond we might go in another direction.

Thanks, Lorelei!
Everything you say here is correct. I guess it''s up to the OP to decide what he wants to do now. I do think that you can always make a better decision on buying a diamond with all the help and kindness on Pricescope.
Best,

 

[Lorelei]

Date: 7/13/2009 1:30:25 PM
Author: Black Jade
It's not the clearest photo, but here's a picture of my ACA studs with my blue nile AGS0 (but not branded H & A) in between them. I think you can see what I mean, from the photo, about the quality of both being simply superb. I repeat the stats-- earrings are H VS2 ACA AGS0 from whiteflash.com, .90 and .91 (1.81 ctw) and the ring is F, SI1, AGS0 but not branded H&A and not Signature Ideal Cut from bluenile.com, in a bluenile platinum setting. .65 carat. I got photos, ASET images and superb service from whiteflash and would recommend them to anybody, but I would also recommend Bluenile.com, depending on the person's personality and how detailed they liked to be when the shopped.
The service at BN is also great. Perhaps the OP would just like to telephone both vendors.

Those are beautiful pieces Jade! I have had a friend buy from BN recently with excellent results, I helped him along the way and their customer service was super and my friend and his young lady were very happy! He bought a non h&a diamond so images weren't an issue and I was able to help him find a diamond with very safe proportions and so it proved, its a beautiful stone. They had just the right diamond available at the time at the right price and it worked out very well indeed.

 

[Lorelei]

Date: 7/13/2009 1:36:16 PM
Author: Black Jade

Date: 7/13/2009 1:25:35 PM
Author: Lorelei

Date: 7/13/2009 1:17:29 PM
Author: Black Jade
Sorry, I didn''t mean to undercut anybody''s advice or to offend.

I just don''t see where the OP says that he definitely wants an H & A. I see where he''s asking what the difference is between H & A and other diamonds and if H&A is worth the price difference.

The technical advice is all great. and it is wonderful how all of you are willing to take your time and give that. I know it has helped me a lot.

I just thought he might like the point of view of someone, not an expert admittedly, who had diamonds both from Bluenile (which he was specifically asking about) and the P''scope vendors that he got recommended to him, especially since there is IS a price difference (which is important to some people). It''s another point of view, that''s all.

You didn''t and don''t worry!

He didn''t say he definitely wanted a h&a, he asked for info so he could understand the difference between h&a and other ideal cuts and whether the premium is worth it, so I linked a tutorial and explained the differences to him. Also I explained the ultimate choice is down to the buyer and their preferences whether to choose a h&a or not, that both BN diamonds showed promise but as to being h&a cuts no way to tell without images. Also we can''t categorically state that any diamond will be an absolute winner really without an Idealscope or ASET image as there is so much info we are missing, faceting, angle variances, optical symmetry and how it all works together, so although some proportion configurations might be a fair bet that we can say '' yes this should be a good looking diamond'' we can''t always say for sure without images.

Bottom line for this poster as I said above, both of the diamonds he is interested in could be great stones, but as to whether they are h&a no way to tell without images, if he is happy to go for non h&a then either of these might fit the bill, if he prefers a '' true'' h&a then a diamond with supporting images is the way to go.


And another POV is fine, if you watch a lot you will see that we try to tailor the advice according to what the poster says they want, if it is a h&a then we have vendors who specialize in these with all the supporting images, if just a well cut diamond we might go in another direction.

Thanks, Lorelei!
Everything you say here is correct. I guess it''s up to the OP to decide what he wants to do now. I do think that you can always make a better decision on buying a diamond with all the help and kindness on Pricescope.
Best,

Thank YOU Jade! I think we do a good service here, it certainly is enjoyable and something I take pride in! Glad you stopped by!

 

[elle_chris]

Date: 7/13/2009 1:33:52 PM
Author: risingsun
When someone comes to PS asking about whether it''s worth the money to buy a h&a diamond, I feel that it is prudent to provide them with education about what a h&a diamond is. There is no pressure to purchase one, but at least there is a point of reference. There appears to be increasing research, which supports a correlation between precision and performance. I will be interested to hear more about this in the future.

You''re right that, it is prudent to provide them with education in regards to what an H&A diamond is. The bottom line is that an H&A diamond is not about light performance but about symmetry.

I honestly don''t mean to sound argumentative but I''d be interested to know about this research that''s being done to show that H&A''s perform better than their ideal counterparts in low light conditions.

Who''s doing this research? What has it shown so far? Are there any articles on it? Or are these observations made by the companies that carry them?

Are you alluding to the fact that you believe that H&A''s out perform other ideal cuts? "If" you are, tell me what you''re basing this on?

 

[mynameisnoah]

thank you all so much for helping me out....i learned a great deal reading your comments and using the links to other resources.

one final question: what is the general consensus regarding GIA graded diamonds VS. AGS graded diamonds?

 

[Black Jade]

Date: 7/13/2009 8:17:56 PM
Author: mynameisnoah
thank you all so much for helping me out....i learned a great deal reading your comments and using the links to other resources.

one final question: what is the general consensus regarding GIA graded diamonds VS. AGS graded diamonds?

They are both very respected. GIA Ex/Ex has, I believe, slightly larger parameters than AGS0. (I may not be phrasing this quite right, perhaps some one else will help out). This link may help you, meanwhile.

http://grading.pricescope.com/

Good luck with your search.

 

[risingsun]

Date: 7/13/2009 2:18:42 PM
Author: elle_chris

Date: 7/13/2009 1:33:52 PM
Author: risingsun
When someone comes to PS asking about whether it's worth the money to buy a h&a diamond, I feel that it is prudent to provide them with education about what a h&a diamond is. There is no pressure to purchase one, but at least there is a point of reference. There appears to be increasing research, which supports a correlation between precision and performance. I will be interested to hear more about this in the future.

You're right that, it is prudent to provide them with education in regards to what an H&A diamond is. The bottom line is that an H&A diamond is not about light performance but about symmetry.

I honestly don't mean to sound argumentative but I'd be interested to know about this research that's being done to show that H&A's perform better than their ideal counterparts in low light conditions.

Who's doing this research? What has it shown so far? Are there any articles on it? Or are these observations made by the companies that carry them?

Are you alluding to the fact that you believe that H&A's out perform other ideal cuts? 'If' you are, tell me what you're basing this on?

This is based upon an interview with Peter Yanzer at the last Las Vegas conference. In an AGS 0 diamond, the more precise the cut, the more likely it is to show a h&a type pattern. Whether or not the stone is designated as h&a, the pattern is there. What is being postulated is that in a superior performing diamond, the precision of the cut has an additive factor. If we left out the term h&a, would this make more sense to you? I don't have any more specifics to offer you.

 

[John P]

Date: 7/13/2009 2:18:42 PM
Author: elle_chris

Date: 7/13/2009 1:33:52 PM
Author: risingsun
When someone comes to PS asking about whether it's worth the money to buy a h&a diamond, I feel that it is prudent to provide them with education about what a h&a diamond is. There is no pressure to purchase one, but at least there is a point of reference. There appears to be increasing research, which supports a correlation between precision and performance. I will be interested to hear more about this in the future.

You're right that, it is prudent to provide them with education in regards to what an H&A diamond is. The bottom line is that an H&A diamond is not about light performance but about symmetry.

I honestly don't mean to sound argumentative but I'd be interested to know about this research that's being done to show that H&A's perform better than their ideal counterparts in low light conditions.

Who's doing this research? What has it shown so far? Are there any articles on it? Or are these observations made by the companies that carry them?

A preface to my comments: I prefer to call 3D cut precision just that - cut precision - rather than H&A, OS, ducks & bunnies or whatever...for two reasons:

1. The term "Hearts & Arrows" sounds gimmicky. This has not been helped by sellers who focus on "cute little patterns" without being able to explain, scientifically, why the diamond may differ in appearance from one with chaotic patterning. Such promotion without knowledge has cast a shadow over the term in my opinion.

2. "H&A" refers only to round diamonds, but 3D cut precision can influence other shapes too.

For Elle - Micro studies of diamond cut only began in the 1980s (credit to Eightstar). Since that time there has been a steady rise in knowledge, especially boosted by computer modeling. As our scanning equipment and computer power gets better more is learned and can be correlated to real world observations. In recent years studies by the American Gem Society, Sergey Sivovolekno & Octonus, the MSU Gemological Center and Dr. Sasian at the University of Arizona have taken us far beyond any of the currently used grading systems, including GIA's and AGSLs.

The AGS Diamond Grading Standards committee researched for 30 years before AGS released its first cut grading system in 1996 and their 3D research was ongoing until the released of the 3D light performance metric in 2005. GIA took 15 years to study before they released their cut grading system for RB in 2006. Right now (my opinion) I'd say Octonus' DiamCalc program and AGSL's diamond-specific ray-tracing research are at the forefront of new knowledge on the subjects of scintillation, dispersion and virtual facets - which are influenced by cut precision (H&A).

The short answer as I know it: Cut precision influences contrast and the resolution of virtual facets, impacting the visibility of dispersion and scintillation. The long answer is...longer.

Here are some links if you're interested.

A primer to understand angular spectrum; a prereq for fwd and reverse ray-tracing IMO.
http://www.agslab.com/spie/spie_lo_res.pdf

A look at ETAS (Effective Total Angular Spectrum) which is closely related to AGSL's scintillation studies.
https://www.cutstudy.com/cut/english/conference_posters/5.htm

A somewhat old/outdated intro to AGSL's scintillation studies. Someone should post any of Peter Yantzer's more eloquent powerpoints, though they may be lacking without his narration.
https://www.pricescope.com/community/threads/agsl-scintillation-studies.63707/

Karl and Garry may have suggestions about basic virtual facet education.

Are you alluding to the fact that you believe that H&A's out perform other ideal cuts? 'If' you are, tell me what you're basing this on?

My answer is that this depends on the diamonds being compared - and what you're looking for. If the 'ideal cuts' have better table, crown & pavilion combos my answer is no: A beautiful 60/60 at 41/33.5/80/55 and a near-Tolk 56/40.8/34.5/55/77 (assume good cut consistency) would both outperform a quote "H&A" unquote that was cut too shallow or deep in my opinion.

Now what if two diamonds are geometrically identical, but one has "perfect" cut precision (H&A) and the other is just a bit less precise? It now becomes a matter of the individual diamonds compared, their size (which affects VFs), the lighting conditions and even how perceptive the viewer is. Maybe no, maybe yes. But as you continue to increase the precision differences the optical differences will be detected. But then taste enters the picture again. There are people who prefer an asymmetrical, chaotic look. No problem -different strokes for different folks.

It's a cool time to be following the studies. I wish more people would. Thanks for asking - I hope the info is interesting.

My advice is to insist on great cut performance as the most important aspect. Those wishing to seek top cut precision should always secure that as a prerequisite.

 

[risingsun]

^^^Thanks for jumping in, John

I appeciate the explanation and am going to follow your links to increase my knowledge base. When I joined PS, you were one of my teachers. Why should it be any different now

 

[elle_chris]

RisingSun- I didn''t mean to single you out, just wanted to know why you believed that H&A''s out performed other ideal cuts that don''t exhibit perfect hearts and arrows.
And in answer to your question, " If we left out the term h&a, would this make more sense to you?" Yes, it would. Because people coming here should understand that a stone with great numbers, a great idealscope/ASET, that''s not labeled an H&A should perform just as well in terms of light return.
Those seeking a great perfomer with perfect symmetry, should definitely go for an H&A.

Joh- Thanks for the links. Haven''t read the first one yet (no time), but the second isn''t working for me.
Totally appreciate your well balanced posts.

 

[stone-cold11]

elle, I can access the second link.

 

[Lorelei]

Date: 7/14/2009 8:08:03 AM
Author: Stone-cold11
elle, I can access the second link.

Weird....I can''t....

 

[vfrhokie]

Try

http://www.cutstudy.com/cut/english/conference_posters/5.htm

(http instead of https)

There''s an invalid security certificate, and depending on your browser, it may reject the site. Technically, there''s no need for security on that location anyway.