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Do Cut Too Deep or Cut Too Shallow RB diamonds even exist???

everstone

Rough_Rock
Joined
Dec 14, 2015
Messages
42
Here's a Wednesday night doozy for you bunch ~

We've all seen the diagrams. "Cut too deep" "Cut too shallow" and "Ideal." But have any of you actually seen (or have) a RB diamond that is cut horribly like the diagrams show? I'm not talking about a depth of 63% (WAHH :(( ) or a pavilion angle of 41.6 (WAHHHH :(( ) for example, I'm talking about REALLY deep or REALLY shallow cuts.

Sure the natural poor performers have their variances (HCAs above 2), but from the side-view they still don't look that bad to the naked eye, and chances are they are shaped more like the "ideal" from the side.

In some ways, I feel like these extreme cut diamonds are more rare than the ideal shape. Somebody prove me wrong. All we ever see on PriceScope are the best, most well-proportioned diamonds. Let's see some horrible ones! :mrgreen:

screen_shot_2015-12-16_at_5.png
 

ADN

Shiny_Rock
Trade
Joined
Nov 24, 2015
Messages
311
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

Do they exist?! Here's one for you...
1ct GVS - Cut-Poor / Polish-Good / Symmetry-Good
MM-5.9 / CA-41 / PA-43.6 / CH-20% / Table-54% / TD-74%
Someone might love it one day... :love:
1ct_poor_cut_diamond.png
 

kenny

Super_Ideal_Rock
Premium
Joined
Apr 30, 2005
Messages
30,617
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

The motivation is not to end up with a deep or shallow stone on purpose.
The motivation is profit.
Getting the heaviest stone possible out of every piece of rough of every shape results in the highest profit.

They got away with this because few customers understood cut.
Even today the vast majority of buyers understand carat weight WAY more than good cut = good light performance.
Just yesterday I heard an ad for 1 carat solitaires for only $1,799. :roll:
Weight is King! :lol:

Why would business people throw away money, weight, cutting for something that few customers understand?
This makes it reasonable for deep and shallows to be very common.
 

solgen

Brilliant_Rock
Joined
Apr 10, 2015
Messages
563
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

I've seen some coworkers diamonds that were terrible. Badly included and terribly cut. These weren't even certed stones. But hey, at least they can say it's a 2ct or 3ct diamond even if it faces up at something .5ct smaller and looks like crushed ice or quartz because of all the inclusions.
 

Andelain

Ideal_Rock
Joined
Mar 10, 2010
Messages
3,525
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

Top4-oldstone-croppedforPS.jpg

ASETPre098.jpg
 

everstone

Rough_Rock
Joined
Dec 14, 2015
Messages
42
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

Any from the side view though?
 

WinkHPD

Ideal_Rock
Trade
Joined
May 3, 2001
Messages
7,516
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

They do exist, and they are UGLY!

One time, say twenty or so years ago, I had a lady in who was getting a divorce and needed to sell her diamond for traveling money.

I estimated the weight at 0.90 cts, but the ring was mounted and I could not measure the depth, only look at it and measure the diameter, 6 mm or so. I could see it was very deep and had a very thick girdle.

She told me it had been purchased at Costco and came with an IGI report on it saying it was a carat.

I told her that I thought the color grade was one or two grades high and that I agreed with the clarity grade given, but that the most I could make it come out to was 0.90 cts and that it might even be less than that. I offered her X dollars and said that if she would wait until the next day I would take it to my bench and have the diamond removed. If it was indeed a 1 ct I would offer X plus Y dollars. (I was right, it was one color grade high, but that is an acceptable variance and the clarity grade was spot on.)

She said no, I am leaving tonight and I need the money. I paid her X and asked her to get a hold of me in a day or two and if it was 1.00 cts I would send her the Y money. She said she would, but I never heard from her again. I pulled the diamond and got a weight of precisely 1.00 cts. I sent it to GIA and got it graded. It came back at precisely 1 ct on the report and when I did the math on the depth divided by the average diameter it came out to 69.5 % or maybe even 70% I do not remember for sure.

I talked about this phonograph needle on Polygon, a jewelers network, and an AGS store called me and asked if I would sell it for them to use to show people how important cut is. I kind of wish I still had it, as it is at least an AGS 9 or 10 and I would love to have it here to show you myself just how ugly a diamond can be, even with a fairly high color and VS clarity.

So, yes, they exist, and yes they are sold to the unwary.

To quote the Sgt on Hill Street Blues, "Hey, be careful out there!"

Wink
 

Andelain

Ideal_Rock
Joined
Mar 10, 2010
Messages
3,525
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

everstone|1450407245|3962884 said:
Any from the side view though?

Sarin_Pre098-cropped.jpg
 

foxinsox

Ideal_Rock
Premium
Joined
Jul 18, 2015
Messages
3,671
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

I have one - it's a shallow OEC - 51.2% depth with a 52% table, shallow crown angle of 11.7%
Somehow despite that it's remarkably pretty, sparkly as hell and throws rainbows all over the place plus it's got that flower under the table which I love about OECs.
img_4160.jpg
 

John P

Ideal_Rock
Trade
Joined
May 1, 2008
Messages
3,563
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

How about these polar opposite bookends?

On the left: 1.00 ct E VVS2 Faint. Weirdly, for the shallow proportions, there's not much spread benefit. Only a 6.68mm average girdle diameter due to XTK girdle and a VL culet which makes for a glass-bottom boat effect, which is appropriate since he's a FishEye. I name him Skippy, for his aquatic-aerodynamic potential.


On the right: 1.00 ct I SI2 Neg. Like stuffing a tall stretchy bag, this cagey cutter foresaw enough vertical weight in a 5.55mm cylinder to hit the magic one-carat mark. However, it will look more like a 60-pointer when set, even in the brightest showroom lights, and you'll be lucky to coax a polite twinkle out of it in soft lighting. Poor little guy. I name him Duckling since there's a beautiful 0.50 ct swan just waiting within him.

The above comments for entertainment. I certainly acknowledge they could be loved as-is. =)

Reports here.
http://www.gia.edu/cs/Satellite?rep...ename=GIA/Dispatcher&c=Page&cid=1355954554547
http://www.gia.edu/cs/Satellite?rep...ename=GIA/Dispatcher&c=Page&cid=1355954554547

poor-shallow-poor-deep.jpg
 

Andelain

Ideal_Rock
Joined
Mar 10, 2010
Messages
3,525
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

Those are painful to even look at the reports! :sick: :nono: ;( :errrr: :knockout:
 

kenny

Super_Ideal_Rock
Premium
Joined
Apr 30, 2005
Messages
30,617
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

:knockout: :knockout: :knockout:

They should have just left them as rough diamonds.
That would have saved even more weight.
 

Andelain

Ideal_Rock
Joined
Mar 10, 2010
Messages
3,525
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

kenny|1450487182|3963296 said:
:knockout: :knockout: :knockout:

They should have just left them as rough diamonds.
That would have saved even more weight.

And they'd have been prettier!
 

gr8leo87

Shiny_Rock
Joined
Apr 24, 2015
Messages
381
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

everstone said:
Here's a Wednesday night doozy for you bunch ~

We've all seen the diagrams. "Cut too deep" "Cut too shallow" and "Ideal." But have any of you actually seen (or have) a RB diamond that is cut horribly like the diagrams show? I'm not talking about a depth of 63% (WAHH :(( ) or a pavilion angle of 41.6 (WAHHHH :(( ) for example, I'm talking about REALLY deep or REALLY shallow cuts.

Sure the natural poor performers have their variances (HCAs above 2), but from the side-view they still don't look that bad to the naked eye, and chances are they are shaped more like the "ideal" from the side.

In some ways, I feel like these extreme cut diamonds are more rare than the ideal shape. Somebody prove me wrong. All we ever see on PriceScope are the best, most well-proportioned diamonds. Let's see some horrible ones! :mrgreen:
First thing first. HCAs above 2 can be performers as good as those under 2. There's no doubt about that. HCA does not take LGF into account. I believe stone with higher HCAs with shorter LGFs can be performers. There's too much dangerous generalization on this forum. On the other hand Reflector images should become the standard along with pavillion view.

On topic: there are ALOT of poor cut in the market. They are sold in packets uncertified and make part of the many commercial produced jewelleries. The jewellery that you see don't have a proper centre stone weight and color mentioned. Always a range. Something like centre stone 0.45 - 0.52ct, I-J, SI3-I1. You can safely assume you are being ripped off. These poor stones that go into the jewelleries are for the average Joe who can boast about wearing 'a full carat' of diamonds.

The poor cut stones that do get certified also stay certified only till they are sold as the buyer would buy poorly cut certified stones for the confidence of color and clarity and then get the girdle inscription polished and use those in the jewellery which will be sold to average joe.

GIA Triple Ex is the rarest cut considering the total amount of diamonds in the market. AGS000 much, much, much more rare. Not because there aren't stones that won't match 000 criteria but mainly because there's a whole world other than USA who has no idea about AGS.
 

pyramid

Ideal_Rock
Premium
Joined
Nov 10, 2002
Messages
4,607
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

gr8leo87|1450528966|3963449 said:
GIA Triple Ex is the rarest cut considering the total amount of diamonds in the market. AGS000 much, much, much more rare. Not because there aren't stones that won't match 000 criteria but mainly because there's a whole world other than USA who has no idea about AGS.

And because there is also a whole world other than USA who has no idea about GIA. I am in the UK and only learned about them from here. Remember the 'A' in GIA stands for America. Mostly HRD for expensive diamonds here, with IGI in chain stores. I asked once about getting a GIA from a jeweller who was the best in a city, and was assured that HRD were just as good and they wouldn't source GIA. They now have about 3 GIA diamonds, about 15 HRD and about 70 IGI.
 

John P

Ideal_Rock
Trade
Joined
May 1, 2008
Messages
3,563
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

Andelain|1450506689|3963398 said:
kenny|1450487182|3963296 said:
:knockout: :knockout: :knockout:

They should have just left them as rough diamonds.
That would have saved even more weight.

And they'd have been prettier!
There's definitely a case to be made there! ;-)
 

John P

Ideal_Rock
Trade
Joined
May 1, 2008
Messages
3,563
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

gr8leo87|1450528966|3963449 said:
First thing first. HCAs above 2 can be performers as good as those under 2. There's no doubt about that. HCA does not take LGF into account. I believe stone with higher HCAs with shorter LGFs can be performers. There's too much dangerous generalization on this forum. On the other hand Reflector images should become the standard along with pavillion view.
RE the red highlighted: I'd add that this must be within reason. Lower Halves tune the character of overall performance. But the Table %, avg Pavilion Angle and avg Crown Angle dictate primary angle of incidence and how much light is returned to the viewer's eye overall. It's physics. Yes, there are cases where a higher order of 3D cut-precision and smart lower half choices can boost brightness where the primary angles are calculated >2 on the HCA. But it gets more limited the farther those angles go above 2.0. Lower Halves cannot 'save' a diamond with too much light failing to return to the eye.

On topic: there are ALOT of poor cut in the market. They are sold in packets uncertified and make part of the many commercial produced jewelleries. The jewellery that you see don't have a proper centre stone weight and color mentioned. Always a range. Something like centre stone 0.45 - 0.52ct, I-J, SI3-I1. You can safely assume you are being ripped off. These poor stones that go into the jewelleries are for the average Joe who can boast about wearing 'a full carat' of diamonds.
Agree 100%.

GIA Triple Ex is the rarest cut considering the total amount of diamonds in the market. AGS000 much, much, much more rare. Not because there aren't stones that won't match 000 criteria but mainly because there's a whole world other than USA who has no idea about AGS.
RE the red highlighted: I wish that would be so, but not anymore. Over the past 10 years mass-producers have learned to game the GIA system. Right now there are more GIA EX diamonds offered for sale than GIA VG, G, F or P. Most are cut to the dubious steep-deep end of EX, which is logical: Mass manufacturers recognize the perceived value of GIA paper in the world's most populous markets and plan as much rough as they can to be cut to the minimal threshold needed for GIA EX where it will retain the most weight.
 

Gypsy

Super_Ideal_Rock
Joined
Aug 8, 2005
Messages
40,225
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

Love the humor John. :wavey:
 

gr8leo87

Shiny_Rock
Joined
Apr 24, 2015
Messages
381
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

pyramid said:
gr8leo87|1450528966|3963449 said:
GIA Triple Ex is the rarest cut considering the total amount of diamonds in the market. AGS000 much, much, much more rare. Not because there aren't stones that won't match 000 criteria but mainly because there's a whole world other than USA who has no idea about AGS.

And because there is also a whole world other than USA who has no idea about GIA. I am in the UK and only learned about them from here. Remember the 'A' in GIA stands for America. Mostly HRD for expensive diamonds here, with IGI in chain stores. I asked once about getting a GIA from a jeweller who was the best in a city, and was assured that HRD were just as good and they wouldn't source GIA. They now have about 3 GIA diamonds, about 15 HRD and about 70 IGI.
There are many consumers in America who have never heard of GIA and are pretty happy with what macy's offer them. A friend bought a bracelet that had 0.30ctw diamonds TW-I3. The metal was brass plated with silver. For 299 dollars. Impulse purchase. Yuckz.

My point: Everyone in trade knows GIA and it's worth. Consumers don't know about GIA even in America.

There's only one reason why I would buy a HRD. Their hearts & arrows grading is pretty top notch. They grade H&A along with all other labs under IDC. However they won't include an actual hearts & arrow image like AGS would. GIA is not under IDC. But if it came to color grading I would go to GIA. And for my stock diamond I would only buy a GIA or perhaps an AGS. Almost all other labs are discounted by the trade.
 

gr8leo87

Shiny_Rock
Joined
Apr 24, 2015
Messages
381
Re: Do Cut Too Deep or Cut Too Shallow RB diamonds even exis

John Pollard said:
gr8leo87|1450528966|3963449 said:
First thing first. HCAs above 2 can be performers as good as those under 2. There's no doubt about that. HCA does not take LGF into account. I believe stone with higher HCAs with shorter LGFs can be performers. There's too much dangerous generalization on this forum. On the other hand Reflector images should become the standard along with pavillion view.
RE the red highlighted: I'd add that this must be within reason. Lower Halves tune the character of overall performance. But the Table %, avg Pavilion Angle and avg Crown Angle dictate primary angle of incidence and how much light is returned to the viewer's eye overall. It's physics. Yes, there are cases where a higher order of 3D cut-precision and smart lower half choices can boost brightness where the primary angles are calculated >2 on the HCA. But it gets more limited the farther those angles go above 2.0. Lower Halves cannot 'save' a diamond with too much light failing to return to the eye.

On topic: there are ALOT of poor cut in the market. They are sold in packets uncertified and make part of the many commercial produced jewelleries. The jewellery that you see don't have a proper centre stone weight and color mentioned. Always a range. Something like centre stone 0.45 - 0.52ct, I-J, SI3-I1. You can safely assume you are being ripped off. These poor stones that go into the jewelleries are for the average Joe who can boast about wearing 'a full carat' of diamonds.
Agree 100%.

GIA Triple Ex is the rarest cut considering the total amount of diamonds in the market. AGS000 much, much, much more rare. Not because there aren't stones that won't match 000 criteria but mainly because there's a whole world other than USA who has no idea about AGS.
RE the red highlighted: I wish that would be so, but not anymore. Over the past 10 years mass-producers have learned to game the GIA system. Right now there are more GIA EX diamonds offered for sale than GIA VG, G, F or P. Most are cut to the dubious steep-deep end of EX, which is logical: Mass manufacturers recognize the perceived value of GIA paper in the world's most populous markets and plan as much rough as they can to be cut to the minimal threshold needed for GIA EX where it will retain the most weight.
Agree with you on the HCA. Anything too much above 2 is certainly rejection. And angles are of primary importance.

But a reflector image will go a long way. And should form basic part of a diamond report. In this age a magnified image of a stone along with an ASET is not difficult to be put on a report - unless there are vested commercial interests - commodotizing diamonds.
 
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