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60:60 vs Ideal MRB proportions – Is beauty in the eye of the beholder? Can one cut fit all?

Rockdiamond

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Karl- I never said conspiracy.
I do feel that when I first started here, years ago, I created a stir- that people on the other side of this discussion did not like.
Have a look at the 60/60 tutorial here on PS- it's basically a heavy handed response to my presence, many years back.
Firstly I think the term 60/60 is rather silly as a diamond description.
You can no more describe a diamond by 2 numbers than you can describe a person with 2 numbers. Would you describe a person as 5'6" 135 with no other information?
This is exactly the point too.
I represent an "old school" approach.
I know of no other PS trade member who has my length of time as a grader, trained the '70's, in a super active market ( NYC)
So I'm bringing a different, more traditional approach to the table.
When we had 60/60's back in the day, GIA reports did not include PA/CA- you had to look at the diamond and judge.
That same practice is still in force here in NYC when seasoned dealers are trading diamonds.
Plus, at the time I realized that this discussion was not going to be restricted to RBC's.
I knew that sellers would start to use the same methods on fancy shapes.
They're not wrong- but neither is my method.
Yet, here on PS- and on much of the internet, we have sellers encouraging folks to "look where the light is" ( re- the story I used as an example above) as opposed to looking at the reality of the diamond.
Then we got devotees of the new methodology to fiercely defend it ( CCL et al)- yet I was the only sane voice on the other side.
Remember, many of the "traditional" diamond people are not internet mavens. This left me standing alone here on PS. But not in the "real world"
Fast forward to today, and this discussion had real world impact on the way RBC's are cut.
Stones cut to hit GIA EX and look like "ideal cut" are simply cut too deep, to my eye.
The resultant loss of spread can be easily correlated.
6.5 was the minimum spread for a super well cut one carat stone in the '90's
 

pyramid

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Weird if the ideal cut is an internet conspiracy then why did I see a commercial last night for a local b&m advertising ideal cut diamonds?

It has been a lot of years now, so if you can't beat them join them. Just like lots of jewellers in this country anyway started putting colour and clarity on their diamond displays after the internet became popular.

Another thing Rockdiamond said about larger facets and a three carat rock showing more fire than a one carat. The same thing as you know is apparent in the chunky facet old cuts, everyone is raving about the pastel colours, those colours are fire.
 

Rockdiamond

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SimoneDi,
A diamond like yours is exactly what I have been bugging David to offer for over a decade. There is nothing to dislike.
On this...let's be honest Karl.
I was booted about 10 years back by the old mgmt.
I came back in 2014 in response to you calling one of my stones "wonky"
Nowadays, we have mended fences- and work together.
But back then, you weren't encouraging me to do anything positive. We were totally on opposite sides of the fence.
Plus, looking at the ( from my perspective) one sided discussion, it would have been a waste of time and money for us to seek out and stock 60/60 RBC's for PS members.

Another thing Rockdiamond said about larger facets and a three carat rock showing more fire than a one carat. The same thing as you know is apparent in the chunky facet old cuts, everyone is raving about the pastel colours, those colours are fire.
BINGO!!
That's a huge reason that "fire" is a red herring.
Discussing "fire" as an advantage of a diamond without discussing actual facet size is misleading.
A poorly cut stone can conceivably have more fire than a super well cut stone.

PS- please call me David......I would have had the user name DiamondsbyLauren- but when I came back ( thanks to Karl) in 2014, the user name was not possible, because of my former membership
 

Texas Leaguer

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Interesting, but to be clear, the comparison is to a 60/60 with relatively shallow crown (31.5) and steep pavilion (41.4), which has HCA=3.
Drk,
That’s a good observation. This comparison was not specifically aimed at 60/60, but rather was intended to visually demonstrate an important beauty aspect that is not widely understood by consumers and not always easy to asses. And to point out the role that cut quality plays in determining whether a consumer will get the full benefits of fire. And I think it is more instructive when you can see that difference between two stones that are widely considered to be very well cut. (rather than say an ideal versus a poorly cut stone)

It does show that diamonds cut for extra ‘spread’, even ones with the top GIA grade for cut, can be making a demonstrable sacrifice in fire. (the 1.01 carat stone in the video has a diameter over 6.6mm)

And as you point out, with a score of 3, this particular stone also validates the HCA and its intended use to filter out potentially problematic stones. Even though HCA generally favors bright stones with good spread, it would have successfully tipped a consumer off that this stone was making tradeoffs that might be significant.
 

flyingpig

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There are really good 60/60s. Personally, I would buy 60/60s with certain CA and PA combos (I provide a link previously). For me, it is easy. A magnified photo, IS, ASET, and proportions numbers give me a reasonably good idea how a diamond will perform. I can picture its 3D appearance. But for most consumers who have very limited experience with diamonds, I just recommend them to go out and see different cut styles in person, just like we recommend people to go out to see and try different settings and compare diamonds of different colors. It is really a fun date with your SO or even by yourself. If you really like 60/60, rose cut, vintage, crushed ice, or TIC, then people here will help.
 
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Rockdiamond

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Hi Bryan- what's your comment on the importance of actual facet size with regards to fire.
You used the example of a one ct spreading 6.5mm, HCA3
Can someone (re)post the link please?

My point is that if fire is the main goal, a one ct round is simply not the best vehicle. No matter how well it's cut.
 

Rockdiamond

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Thanks Pyramid- I did see the page.
I really want to avoid any criticism of any site or company. I know Bryan put a lot of effort into that page- and it's lovely.
Hopefully, we can discuss the issues right here- such as my point about size.
 

Karl_K

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Hopefully, we can discuss the issues right here- such as my point about size.
Sure size makes a difference, however telling someone that is looking for a 1ct with nice fire to buy a 3ct is not going to fly.
I have enjoyed the fire show from diamonds ranging from melee to 5+ct its all about finding the right lighting.
 

Dizzie

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I am reading this thread with a lot of interest. One thing that might be helpful for many members - would it be possible to put a cheat sheet of "safe angles" for non-TIC stones?
 

Rockdiamond

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Sure size makes a difference, however telling someone that is looking for a 1ct with nice fire to buy a 3ct is not going to fly.
I have enjoyed the fire show from diamonds ranging from melee to 5+ct its all about finding the right lighting.
This is a great point Karl
But my point is that PS discussion of fire needs to include size.
For example- a consumer looking for a one carat stone being advised that it's not good for lack of fire is being mislead unless the discussion includes the fact that a one carat OMB or other "chunky" stone is likely to have a lot more perceivable fire IMO.
Also, I'm a bit skeptical of claims of .02ct stones having perceivable fire in any significant proportion.
 

Rockdiamond

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Verrrrry Interrresting....
I just got a request for a stone from a client.
The first candidate that showed up is a great specimen for this discussion.
It's an important diamond, over $50k

60 table
61.3 depth
80% lgf ( this is another important ingredient)
GIA XXX

Before I go further- the stone would get trashed here.
The HCA is......
get ready....
6
I should reject it out of hand, right?
 

Karl_K

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Verrrrry Interrresting....
I just got a request for a stone from a client.
The first candidate that showed up is a great specimen for this discussion.
It's an important diamond, over $50k

60 table
61.3 depth
80% lgf ( this is another important ingredient)
GIA XXX

Before I go further- the stone would get trashed here.
The HCA is......
get ready....
6
I should reject it out of hand, right?
pavilion angle?
 

Rockdiamond

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CA 33
PA 41.8
 

Karl_K

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Rockdiamond

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It's a G Karl- but it faces like an F ( no fl)
 

Karl_K

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It's a G Karl- but it faces like an F ( no fl)
Sorry all the wishful thinking in the world doesn't change physics.
I was coming back to say that it was potentially a diamond that you would like and potentially not a train wreck. (that is not a put down to you David, you like splintery looking diamonds)
It potentially bats higher than its AGS/HCA grade implies if you don't consider the color entrapment and the edges aren't overly weak.
However reality here:
color entrapment is a given
There is the potential for reduced brightness out on the edges of the diamond depending on the specifics to what degree.
An ASET image would be interesting.
 

Rockdiamond

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Let me get this straight Karl- I shouldn't trust my lying eyes that the stone faces up very well for a G???
It does sound kind of.....silly, no?

In terms of brightness- it's a very bright stone from the edges in.
It's a hard stone NOT to like......

( ETA- A woman comes home to find her husband in bed with another woman. He walks out of the room like nothing happened.
"Who's that woman???"
What woman.
"The one I just saw you in bed with!"
There's no woman. Who are you going to believe- me or your lying eyes.....
We need a little humor)
 

Karl_K

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Let me get this straight Karl- I shouldn't trust my lying eyes that the stone faces up very well for a G???
It does sound kind of.....silly, no?
Real unbiased opinion you have there. ;-)
I get it you love this type of diamond that does not mean it does not have flaws and that everyone else should love it too.
I was even willing to say nice things about its potential based on the information provided.
Lets stick to reality here.
 
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Karl_K

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David I will match your funny:

A woman goes to bed with her husband.

The next morning she wakes up and he’s gone.

She runs across the street and knocks on the neighbor lady’s door.

Her husband answers the door and she demands an explanation.

“Sorry honey, the laws of nature quit working and I floated to the neighbor lady’s bed.”
 

Rockdiamond

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Lol!!!

Karl, I'm not trying to convince anyone to buy this diamond. I HAVE TO look at it with unbiased eyes.
We have a money back guarantee- so if there's a defect or noticeable problem with a diamond, it will come back and bite me in the a$$.

I get that you love Ideal diamonds, but that doesn't mean everyone should accept their flaws, ( reduced spread and scintillation) and that everyone needs to love it to.
See? Calling things flaws based on science which does not jibe with reality is an issue.
Traits would be a better word than flaws.
Important to point out that spread- especially when a stone has the "splintery" look produces a larger looking diamond. You can't argue with measurements Karl- the stone has a great spread for the weight.
I know for a fact, size is important to this buyer.
 

gm89uk

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@Rockdiamond, still waiting for an example 60:60 stone that you love, when you come across it.
 

Rockdiamond

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@Rockdiamond, still waiting for an example 60:60 stone that you love, when you come across it.
The diamond which happened across my desk today is a pretty good example, although not my "dream" stone.
Holding it next to a super ideal I have here, I can easily observe that the differences in general light performance- the stones are not all that close in carat weight, or color
The super ideal does have brighter singular flashes. The not quite 60/60 has more flashes- and spread out in a way I could easily find more attractive. Or not.
There's no denying the beauty of cut on the Super Ideal.
But there's also no denying the almost 60/60 is amazing as well.
I love larger round diamonds......fun to play with.

Another SUPER crucial point: Diamonds of this size/clarity/value/XXX/ don;t grow on trees.
For a buyer of a stone like this, you need to look at the opportunity.
As a hypothetical example-
Let's say you have $60k to spend.
Assume all diamonds are the same color/clarity, all GIA X cut and at least VG/VG
You can get a 3.20ct 60/60 spreading 9.45
or a super ideal 3.00 spreads 9.2
Or a 60/60 VG Cut EX/EX 3.00 spread 9.3 and $7k change.

For my money, ALL three can be objectively said to be equally viable.
But for many years here, you'd have to believe anyone choosing the non super ideal was automatically getting some lump of carbon. Or has Karl just told me- it has "color retention". Karl- I love ya man. And I greatly respect your knowledge that brings you to that conclusion.
It's just that sometimes the theory and the reality don't jibe
 

Karl_K

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It's just that sometimes the theory and the reality don't jibe
Reminds me of a story....
A young boy ran out the door and threw his ball up in the air.
It came down and hit him on the head.
He ran inside crying "Mommy Mommy the ball bounced off the sky and hit me in the head! :)
 

Rockdiamond

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Mommy mommy- why am I running around in circles.
SHUT UP OR I'LL NAIL YOUR OTHER FOOT TO THE FLOOR

All joking aside-
Bryan- I apologize.
My comment earlier was written too quickly- and overly glib.
The page you authored is lovely- in the best way.
You put it together in a professional, and easy to read presentation.
You're perfectly utilizing research you believe to be reliable- and scientifically obtained.
But the findings and interpretations of AGSL are by no means universally accepted.
GIA's interpretation of scientifically obtained cut data far outsells AGSL graded diamonds. We all agree GIA goes too far at the edges of EX Cut grade. And we all agree the vast majority of the market is neither super ideals- nor the 60/60 I'm speaking of. Most commonly cut RBC diamonds today utilize GIA cut grade width to sell overly deep diamonds.
Let's put aside market differences and conclusions of AGSL and GIA. Even connoisseurs of fine cut debate the balances of scintillation spread and contrast.
So, I totally respect the page, and how it presents your interpretation of light performance data.
But reach different conclusions.
 

Rockdiamond

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Also- this is by no means any criticism of the HCA, (or Diamondseekers chart) which does what it's supposed to do.
You can't get a stone that was cut at the bad edges of the GIA cut grade if you use the HCA.
But like any filter system, there's going to be some specific examples that prove to be false negatives.


If I'm holding the stone in front of me, I'm going with what my eyes tell me.
 

Rockdiamond

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But reach different conclusions.
Meant to say,
But I reach different conclusions
We're all, of course, free to draw our own conclusions
 

Dancing Fire

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pyramid

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I can see the benefits of ideal cut diamonds but maybe there is two flavours. I don't know about others who are younger, but I never saw an ideal cut for many years but was still drawn to the beauty of diamonds. So it is the fact that diamonds or most diamonds are beautiful anyway. So why curtail it by cut, let people choose and have both reduced spread or scintillation if we believe that and also diamonds with more spread and in between. I mean even those little cluster rings in British shops, I mean not well cut melee and probably included, 1 or 2 point diamonds and less, they sparkle in the sun beautifully even if they are showing brilliance and no fire. Different price points but all sparkly.:)
 

pyramid

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Ideal Cut means lower colors SELL. Lesser cuts means more spread from the rough which also SELLS. This is all marketing. Diamonds are beautiful because of their refractive index, all the rest is a marketing ploy (I think). Both these products appeal to people who want beautiful diamonds, the bigger the better. So customer wants SIZE and vendors want to SELL. Let us have both at different price points, lower color means less cost and lower cut means less cost. Why does ideal cut need to be seen as the best, it is just a marketing word 'ideal' used to sell a product. IS IDEAL CUT ONLY SEEN AS THE BEST ONLINE, not in real world as GIA doesn't use it. So David's stones (well some of them as he says he sells ideal cut too) need a new name and another lab like AGS as remember Ideal is not used by the king of labs GIA, they use excellent. So another name could be Top Proportion diamonds.
 
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