New Line of Brian Gavin Signature Cushion Cuts

[Todd Gray]

Todd,

What am I, chopped liver that you suddenly leave me out of these discussions? I, your roomy at so many of these discussions?

Sigh.

For what it is worth, the AGS laboratory has worked with people who have patented a new cut to measure them as they wish them measured for ten or twelve years now. They figure that the people who invented the cuts know how they want them measured. Seems reasonable to me.

I have no dog in this fight, other than to say that I think the new stone looks very nice and I applaud Brian for spending the many tens of thousands of dollars necessary to come up with it. I hope it works for him.

Wink

P.S. Being from Idaho I will bring the potatoes...

No man, you're always invited, it goes without saying, but you weren't on the board, hadn't commented, so I wasn't going to drag you into it... But potatoes are always welcome, it's been too long!

And Yoram should come also, I got a chance to meet him at JCK and he's cool peeps

 

[John P]

Perhaps this is one of those debates which we should have out on Pollard's back deck, over a beer and some barbecue

Open invitation Todd. Many of you have been here, so you know the way. The pool is open. The grill is hot. No glassware on the deck...I have plastic cups for everyone; kosher and infidel alike.

 

[Karl_K]

Perhaps this is one of those debates which we should have out on Pollard's back deck, over a beer and some barbecue, because I don't think it's going to be solved here, we can invite Brian over from Houston, I'll fly in from California, Peter can fly in from Vegas, Paul can fly in from Antwerp, and Garry can fly in from Australia (I'll bring him some wine) and I'm going to kick back and watch y'all hash this out, because that will at least remind me of the good old days when everybody would have just been excited that one of us had introduced a new cut, and it gives me an excuse to wolf down some of great food with good friends

Actually this needs to be ironed out here. These diamonds will be discussed here so anyone who wants to help anyone in a cushion thread needs the info.

You want it like the old days... here is a stormism for ya :}
Yawn another h&a cushion wake me up when something interesting happens.
I wish Brian the best selling them but honestly it seems kinda me too at this point and I have a hard time getting excited about it. It doesn't fill a hole in the market.

 

[Serg]

There is only one way to refer to spread, and AGS use it in calculations for rounds only. it should be used for all cuts if we are really serious about " labs are for consumer confidence".
All shapes and cuts should be compared to a single round cut standard. Full stop.

I agree that there theoretically should be a standardized measure, but I'm not sure that making the average diameter of a diamond the denominator (as they do with rounds) is the solution. What about emerald cuts and ovals and marquis and pears and other shapes that weren't intended to be perfectly round or square? As a consumer, the depth percentage even within the same fancy shape would be nearly meaningless.

For all modified shapes, AGS just needs to be clear about what's being measured. The first thing I want to know is how big the thing is, and that's impossible if I don't know what's being measured. Just put a diagram on the lab report like the one Todd Gray made and the problem is solved.

Average diameter is not necessary to calculate Spread.
http://www.octonus.com/oct/products/3dcalc/standard/param17.phtml
"OctoNus spread

Spread is a parameter that shows the difference between weight of a given diamond and weight of the standard diamond. The standard diamond has the same area as the given diamond but the standard diamond has Tolkowsky proportions with the medium girdle thickness. The spread parameter tells if your diamond looks more or less massive than it really is.

"

 

[bur_gwah]

All measurement issues aside, are there any obvious downsides to this cut? I landed on this H&A cushion cut without realizing it was brand-spanking-new. Anyone have any pics yet?

 

[GoSounders]

I just got my 0.723ct I SI2 BGD Cushion today.

Stone looks very bright and definitely outperformed the 3 generic cushions I put it up against (2 by a landslide, 1 by a lesser margin, all more expensive retail shop stones).

Pardon the cell phone picture and man hand. You asked

 

[Paul-Antwerp]

Hey Todd,

Time well spent gives more knowledge and perspective. As for the notation of measurement, it seems now that this is a problem encompassing a high number of shapes, and most probably a multitude of labs. AGSL had the problem of me easily finding two almost identical stones in actual measurement with a completely different notation. BGD had the problem of this suddenly about their specific example.

I feel a need for an agreed convention between all labs to use the same notation-system. This is about physical measurement, not about the subjective borderline of colors or clarities. I would expect that the public expects this to be uniform.

Sorry for the threadjack. That is mostly due to you incorrectly explaining the full notation, and referring to me, also incorrectly, as the validation for such notation. I needed to correct that.

Live long,

 

[Todd Gray]

Hey Todd,

Time well spent gives more knowledge and perspective. As for the notation of measurement, it seems now that this is a problem encompassing a high number of shapes, and most probably a multitude of labs. AGSL had the problem of me easily finding two almost identical stones in actual measurement with a completely different notation. BGD had the problem of this suddenly about their specific example.

I feel a need for an agreed convention between all labs to use the same notation-system. This is about physical measurement, not about the subjective borderline of colors or clarities. I would expect that the public expects this to be uniform.

Sorry for the threadjack. That is mostly due to you incorrectly explaining the full notation, and referring to me, also incorrectly, as the validation for such notation. I needed to correct that.

Live long,

I apologize if you feel that I referred to you incorrectly Paul, let me explain how that happened and perhaps you can provide further clarification.

I began by simply explaining that the diamond is being measured tip-to-tip, your article provides several different ways which a princess cut diamond can be measured in comparison to a round. Your first example, shows a Crafted by Infinity Princess Cut Diamond which measures 5.78 x 5.78 x 4.60 mm based on measurements which were taken edge to edge.

Then you provide an example of the same diamond with a tip-to-tip measurement as the first measurement and an edge to edge measurement as the second measurement, resulting in 8.17 x 5.78 x 4.60 mm, as a second example.

A little further down the page, you reference a Hearts on Fire Dream diamond, which is a cut cornered square, and reference the measurements as 7.12 x 5.94 x 4.41 mm, which clearly is notated in the same manner as example #2 in your article. Then you make the statement "With the Dream Diamond being a proprietary cut, the company itself can choose how the measurements are presented."

I mentioned your article, because I felt that it provided insight into the different ways that a fancy shape diamond might be measured AND because it eluded to the fact that proprietary cut diamonds might be measured differently...

I think that the problem might have arisen, when I used a comma, instead of a period, between the statements "this refers to the true diameter of the diamond" and "Paul Sleger's article... will provide some insight to this regard." However I do think that your article provides "insight" into the different ways which these diamonds can be measured, it seems like an accurate statement to me, and it was intended so that people would go to the article and read it, which would provide them with the insight about how diamonds of similar shape might be measured differently...

And based on some rather in-depth discussions that I had with Brian about why the AGS is measuring his diamond from tip-to-tip, it is because they feel that it best represents the diameter of the diamond... I guess I should have started out writing a book, rather than making a simple statement on the fly, I was just trying to answer the question in the fastest way possible and apparently it led to a myriad of confusion and caused you to feel that you had been misquoted, or improperly referenced, my apologies.

Hopefully what I'm trying to say makes sense now, and people will understand that the reference to your article is to provide additional insight into how diamonds may be measured differently (and how that will change the measurements) and understand why it was provided as a reference.

I have a myriad of photographs which are intended to be used as part of a tutorial about why this diamond is being measured the way that it is, I'd post them as part of the explanation because a picture is worth a thousand words and all that, but I'm afraid that doing so might violate the forum rules, since the photograph of the diamond which I posted apparently upset some people... but suffice to say that I can see the argument as to how this diamond should be measured from both sides, and I don't have a dog in this fight (to quote Wink) I was just trying to explain how it IS being measured.

And I completely agree that the labs should provide some sort of reference as to how they are measuring the diamonds, given all of the variations currently in use do to the nature of proprietary cuts, that would solve most of the issue in my opinion, both in terms of consumers interpretation of the measurements, but also with regard to the retail trade. Suffice to say, the differences in how all of these diamonds are being measured is likely to be an ongoing issue, but hopefully we've at least figured out that this particular cut is being measured from tip-to-tip and we'll be able to answer that question adequately when it is posed by consumers on this forum.

 

[teobdl]

Serg--
How would you calculate D (Diameter) for a pear in your spread formula? What about a radiant?

Lastly, if one really wants to compare face up sizes among weights, then why not just take face up 2d area?

 

[Serg]

Serg--
How would you calculate D (Diameter) for a pear in your spread formula? What about a radiant?

Lastly, if one really wants to compare face up sizes among weights, then why not just take face up 2d area?

Teobdl,

did you find Diameters in Our spread method?


"Spread is a parameter that shows the difference between weight of a given diamond and weight of the standard diamond. The standard diamond has the same area as the given diamond but the standard diamond has Tolkowsky proportions with the medium girdle thickness. The spread parameter tells if your diamond looks more or less massive than it really is."

 

[teobdl]

Serg-got it now. Thanks. Maybe spread should be on the AGS report. It would certainly help consumers make decisions.

In other news, BGD has seen our measurement troubles. Here's their explanation and rationale:
http://www.briangavindiamonds.com/signature-cushion-measurements-explanation?utm_campaign=Cushion%20Launch&utm_source=exacttarget&utm_medium=email&utm_content=click+here+-+email+2

 

[delight]

It seems that the cushion cut diamonds have "wonky" optical symmetry and has variances from one stone to another if you were to examine it critically. Unlike the Brellia which shows consistent quality in optical symmetry and performance (at least from ASET), this new line of cushions doesn't seem to compare well.

Is it just me or do others feel the same?

 

[yssie]

Serg-got it now. Thanks. Maybe spread should be on the AGS report. It would certainly help consumers make decisions.

In other news, BGD has seen our measurement troubles. Here's their explanation and rationale:
http://www.briangavindiamonds.com/signature-cushion-measurements-explanation?utm_campaign=Cushion%20Launch&utm_source=exacttarget&utm_medium=email&utm_content=click+here+-+email+2

Perfectly explained - and good for them for writing that up so quickly! This way new consumers won't have to find this thread on PS to understand what's going on (with this brand at least)

It seems that the cushion cut diamonds have "wonky" optical symmetry and has variances from one stone to another if you were to examine it critically. Unlike the Brellia which shows consistent quality in optical symmetry and performance (at least from ASET), this new line of cushions doesn't seem to compare well.

Is it just me or do others feel the same?

Can you post an example?

 

[GoSounders]

It seems that the cushion cut diamonds have "wonky" optical symmetry and has variances from one stone to another if you were to examine it critically. Unlike the Brellia which shows consistent quality in optical symmetry and performance (at least from ASET), this new line of cushions doesn't seem to compare well.

Is it just me or do others feel the same?

The cut does vary between stones. I also agree that the ASET performance doesn't quite measure up to the Brellia, which I believe has extremely strict parameters. However, I'm not sure how much difference that little bit makes in the real world. At the same price, I'd take the Brellia, but it's usually a premium.

This one has an especially chunky arrow pattern:
http://www.briangavindiamonds.com/diamonds/diamond-details/0.898-i-vs2-cushion-diamond-ags-104065184006
Compared to:
http://www.briangavindiamonds.com/diamonds/diamond-details/0.728-j-vs1-cushion-diamond-ags-104065051014

 

[yssie]

Oh, that's interesting! It looks like BGD has defined this brand differently from their H&A RB line - they've specified a wider range of acceptable parameters that translates into a wider variety of flavours.

I don't think there's anything wrong with that - it means that the coconut macaroon and dulce de leche lovers can get branded stones too, if they want them, alongside the usual vanilla/chocolate/strawberry folk

 

[teobdl]

I agree that there seems to be lots of variance in the pavilion thickness.

The commentary on the BGD website suggests that the BGS cushion looks bigger than its equivalent weight BGS round (i.e. that the 1.66 ct cushion actually spreads as well as a 1.8 ct round). I read the words and was partially swayed. I then looked just at graphics, and to me, the 1.66 cushion looks closer to the 1.52 ct round.

Anyone else have thoughts on the cushion vs round spread?

The elephant in the room is that the most helpful comparison is missing: 1.66 BGS cushion vs. 1.66 ct BGS round.

 

[Todd Gray]

Hey Paul,

Thank you for the email this morning discussing this in depth, now I understand what you were saying and you're absolutely correct, the first measurement is the longest tip-to-tip measurement, the second measurement is the shortest edge-to-edge measurement. I've verified this with Brian Gavin as being correct, and updated the image as attached. Thanks again for the help, and for alleviating my confusion.

 

[Karl_K]

Hey Paul,

Thank you for the email this morning discussing this in depth, now I understand what you were saying and you're absolutely correct, the first measurement is the longest tip-to-tip measurement, the second measurement is the shortest edge-to-edge measurement. I've verified this with Brian Gavin as being correct, and updated the image as attached. Thanks again for the help, and for alleviating my confusion.

The mixing of the 2 measurements is the problem.
The stone is not the A x B listed on the report because A and B are different measurements.
That is not right and against how everyone expects diamonds to be measured on a report.
I consider that confusing and deceptive.
Because it is called a cushion it should be measure like any other cushion they issue a report for.
That is just common sense.

edit:
That is also against what Brian says here:
http://www.briangavindiamonds.com/signature-cushion-measurements-explanation?utm_campaign=Cushion%20Launch&utm_source=exacttarget&utm_medium=email&utm_content=click+here+-+email+2
"So the AGSL measures the diamond from tip to tip, which takes the full surface area of the diamond into account to determine the diameter of the diamond. The measurements of our Brian Gavin Signature Cushion Cut Diamonds can be a little confusing at first glance, because they tend to give the impression that the diamonds are rectangular in shape. For instance, the measurements of the 1.662 carat, F-color, VVS-2 clarity, Brian Gavin Signature Cushion Cut Diamond used throughout this example, measures 7.91 x 6.62 x 4.83 millimeters, which would result in a length to width ratio of 1.19:1.00 if the measurement represented a traditional fancy shape diamond, this gives the illusion that this diamond is slightly rectangular, however as you can see from the photographs, this diamond faces up pretty square.

The variation in the corner to corner measurements are due to the fact that these diamonds are cut by hand, the girdle edge is not bruted as they would be if the diamonds were round brilliants."

That says that both numbers are corner to corner.

 

[Garry H (Cut Nut)]

Hey Paul,

Thank you for the email this morning discussing this in depth, now I understand what you were saying and you're absolutely correct, the first measurement is the longest tip-to-tip measurement, the second measurement is the shortest edge-to-edge measurement. I've verified this with Brian Gavin as being correct, and updated the image as attached. Thanks again for the help, and for alleviating my confusion.

The mixing of the 2 measurements is the problem.
The stone is not the A x B listed on the report because A and B are different measurements.
That is not right and against how everyone expects diamonds to be measured on a report.
I consider that confusing and deceptive.
Because it is called a cushion it should be measure like any other cushion they issue a report for.
That is just common sense.

edit:
That is also against what Brian says here:
http://www.briangavindiamonds.com/signature-cushion-measurements-explanation?utm_campaign=Cushion%20Launch&utm_source=exacttarget&utm_medium=email&utm_content=click+here+-+email+2
"So the AGSL measures the diamond from tip to tip, which takes the full surface area of the diamond into account to determine the diameter of the diamond. The measurements of our Brian Gavin Signature Cushion Cut Diamonds can be a little confusing at first glance, because they tend to give the impression that the diamonds are rectangular in shape. For instance, the measurements of the 1.662 carat, F-color, VVS-2 clarity, Brian Gavin Signature Cushion Cut Diamond used throughout this example, measures 7.91 x 6.62 x 4.83 millimeters, which would result in a length to width ratio of 1.19:1.00 if the measurement represented a traditional fancy shape diamond, this gives the illusion that this diamond is slightly rectangular, however as you can see from the photographs, this diamond faces up pretty square.

The variation in the corner to corner measurements are due to the fact that these diamonds are cut by hand, the girdle edge is not bruted as they would be if the diamonds were round brilliants."

That says that both numbers are corner to corner.

I would like to invite anyone from BGD to join the discussion.
I find it hard to understand that this cut can have a bigger spread than a well cut round of the same weight?
The simple way to verify this is for someone to run a few stones on a scanner and enter them into DiamCalc where the spread is given on all cuts with the rules that Sergey posted.

 

[teobdl]

Interesting that the price per ct is much lower than an equivalent weight round, despite maybe similar performance characteristics. Is this, at least in part, because cushions tend to waste less rough?

One rough octahedral diamond fits 2x 4-sided diamonds better than 2x circular diamonds.

 

[GoSounders]

After receiving my stone on Monday, Brian Gavin actually called me today to make sure I was happy with my purchase. I guess he's only sold about 10 of these stones thus far, so he's been getting in touch with customers of his new cut.

He clearly has a lot of pride in this stone, and we talked about the difficulties in getting a round's patterning into a cushion cut shape without having a super-thick girdle on the sides. I mentioned that I had difficulty seeing all 8 arrows simultaneously without the H&A viewer or magnification, and I chalked it up to the smaller size of my stone, but BG mentioned that was a slight compromise made by the extra 4 facets keeping the girdle uniform throughout. Someone with more technical knowledge of H&A could probably elaborate on that.

I didn't press him about the dimensions, as I didn't find them confusing. The stone is obviously not rectangular, so there's nothing else those dimensions can be. However, the sales dept still says both measurements are tip-to-tip.

 

[Lula]

Perhaps this is one of those debates which we should have out on Pollard's back deck, over a beer and some barbecue, because I don't think it's going to be solved here, we can invite Brian over from Houston, I'll fly in from California, Peter can fly in from Vegas, Paul can fly in from Antwerp, and Garry can fly in from Australia (I'll bring him some wine) and I'm going to kick back and watch y'all hash this out, because that will at least remind me of the good old days when everybody would have just been excited that one of us had introduced a new cut, and it gives me an excuse to wolf down some of great food with good friends

Actually this needs to be ironed out here. These diamonds will be discussed here so anyone who wants to help anyone in a cushion thread needs the info.

You want it like the old days... here is a stormism for ya :}
Yawn another h&a cushion wake me up when something interesting happens.
I wish Brian the best selling them but honestly it seems kinda me too at this point and I have a hard time getting excited about it. It doesn't fill a hole in the market.

I don't think it's a yawn at all. It's great to have another vendor to recommend for H&A cushions. Especially for those of us not comfortable recommending GOG.

 

[Lula]

After receiving my stone on Monday, Brian Gavin actually called me today to make sure I was happy with my purchase. I guess he's only sold about 10 of these stones thus far, so he's been getting in touch with customers of his new cut.

He clearly has a lot of pride in this stone, and we talked about the difficulties in getting a round's patterning into a cushion cut shape without having a super-thick girdle on the sides. I mentioned that I had difficulty seeing all 8 arrows simultaneously without the H&A viewer or magnification, and I chalked it up to the smaller size of my stone, but BG mentioned that was a slight compromise made by the extra 4 facets keeping the girdle uniform throughout. Someone with more technical knowledge of H&A could probably elaborate on that.

I didn't press him about the dimensions, as I didn't find them confusing. The stone is obviously not rectangular, so there's nothing else those dimensions can be. However, the sales dept still says both measurements are tip-to-tip.

Interesting way to solve the thick girdle issue. Thanks for posting your impressions of your new diamond. More photos, please, when you can. From the one photo you posted, it looks like the diamond is very pretty.

 

[GoSounders]

Interesting way to solve the thick girdle issue. Thanks for posting your impressions of your new diamond. More photos, please, when you can. From the one photo you posted, it looks like the diamond is very pretty.

My sister took my camera and she's 3000 miles away, so my phone is all I've got. Any requests for lighting/background/distance?

Stone will probably go in to get set next week.

 

[Lula]

https://www.pricescope.com/community/threads/how-to-take-good-photos-of-your-diamonds.102989/
This thread has some suggestions on how to get good photos. And it takes some practice, some trial and error, with lighting and cropping.

 

[Garry H (Cut Nut)]

Perhaps this is one of those debates which we should have out on Pollard's back deck, over a beer and some barbecue, because I don't think it's going to be solved here, we can invite Brian over from Houston, I'll fly in from California, Peter can fly in from Vegas, Paul can fly in from Antwerp, and Garry can fly in from Australia (I'll bring him some wine) and I'm going to kick back and watch y'all hash this out, because that will at least remind me of the good old days when everybody would have just been excited that one of us had introduced a new cut, and it gives me an excuse to wolf down some of great food with good friends

Actually this needs to be ironed out here. These diamonds will be discussed here so anyone who wants to help anyone in a cushion thread needs the info.

You want it like the old days... here is a stormism for ya :}
Yawn another h&a cushion wake me up when something interesting happens.
I wish Brian the best selling them but honestly it seems kinda me too at this point and I have a hard time getting excited about it. It doesn't fill a hole in the market.

I agree Karl,
If these stones are being sold as H&A's this should raise the usual Pricescope questions of evidence.
I doubt this stone can show good patterning.
http://www.briangavindiamonds.com/d...nd-ags-104065051017#!prettyPhoto[gallery2]/1/

 

[GoSounders]

I agree Karl,
If these stones are being sold as H&A's this should raise the usual Pricescope questions of evidence.
I doubt this stone can show good patterning.
http://www.briangavindiamonds.com/d...nd-ags-104065051017#!prettyPhoto[gallery2]/1/

Woah, that is one hell of an ugly duckling. How does that score an Ideal 0 grade for symmetry?

 

[Paul-Antwerp]

Calling that an ugly duckling is not one, but many bridges too far.

Lab-graded symmetry is generally a grade of meet-point-symmetry, and I see no reason to doubt the lab-grade of Ideal in this respect.

Live long,

 

[GoSounders]

Calling that an ugly duckling is not one, but many bridges too far.

Lab-graded symmetry is generally a grade of meet-point-symmetry, and I see no reason to doubt the lab-grade of Ideal in this respect.

Live long,

True, I was a bit harsh, as I'm sure this is still a very nice diamond. Then again, I'm not sure how one can market this as a H&A stone with the patterning like this. Add that to the light leakage through the center not seen in the other BGD Signature Cushions, and this is clearly an anomaly.

I think he would be well-served in downgrading this one to a BG Select.

 

[delight]

I don't think this is an anomaly. There are many others with significant variation in optical symmetry and ASET.