Cut and grading....

[AprilBaby]

Pardon my rambling; I have bad insomnia tonight. I'm laying here thinking about various questions that come up and here are a few I have:

1. If we all want the best cut stones regardless of shape, why do cutters produce poorly cut stones? Inexperience? Lack of knowledge?

2. So the cutter has a stone that's not going to make a good GIA/AGS candidate. It goes to Egl/IGI. What makes a good GIA candidate over the lower grading houses?

3. If the better stones go to GIA/AGS, technically, for the average person, will they really get a bad stone if they purchase a GIA graded stone? Didn't it already pass some sort of standard to go to GIA in the first place? Most people can't tell one diamond from another. Most of us are cut snobs so we care.

4. Anyone know how to get rid of insomnia?????

 

[Gypsy]

I do not know how to get rid of insomnia. If I did, I'm be a millionaire and would not post as often as I do on PS. I've suffered from it for years. I'm sorry you are experiencing it, it is frustrating.

As for the first question. Better cut stones take more skill to cut (so more expensive labor costs), but also they waste a lot of rough.

Also the industry is slowly realizing the advantages of producing more better cut stones.

And there is a lot of ignorance out there. A lot of people think that "cut" means shape.

 

[Missy]

1-3 already answered by Gypsy.

4. Insomnia. I am sorry you both suffer from this. I can empathize because I do too especially now. Here's what works for me.

One, I take solace in the fact that my body is at least resting when I am in bed trying to sleep even if my brain is not turned off entirely yet. And what helps me is if I have a purring furbaby next to me while I am trying to fall asleep. There is something so peaceful and relaxing about having a sweet kitty near you that just allows you to finally turn your mind off and dream sweet dreams.

Lately Francesca has been sleeping on top of me since I now sleep on my back and it is too cute for words. Wish I had a pic of that but for obvious reasons (I am sleeping lol) I don't. But here is a pic of her laying at/on my feet. Still very soothing. I am so jealous of kitties because of their unique ability (perhaps shared by many animals) to just turn it off and fall asleep almost anywhere at any time. Quite amazing really.

Also just trying to think of pleasant thoughts when I am in bed trying to fall asleep and letting my mind wander but not to any problems or worries. Only thinking about something happy. I just keep my mind from going into problem solving or worry mode. That is reserved for waking hours and not when I am trying to sleep.

Ofc, YMMV and what works for me might not for you but AprilBaby, perhaps worth a try if you love animals and don't have one yet? Or perhaps you can foster one and see how it goes! How are you doing knee wise? I hope all is still going smoothly and you are doing well!

Please excuse my shameless excuse to post more kitty pics...I just cannot resist. LOL lucky I don't have human kids because I would be plastering them all over PS probably hehe.

 

[Missy]

Last one just snapped by my dh a minute ago. See, I practice what I preach.


CCL that I am.

 

[Rockdiamond]

This is a great question and the source of much misunderstanding here on PS
Think of a diamond cutter as an architect who needs to design a building.
If she's got a flat 1/2 acre lot there's plenty of options.
What if there's a stream in the middle-or it's not level.
All of a sudden the designer has to use a lot more creative thinking to use the land well.

Since rough diamonds come in all shapes and colors cutters need to find the best use for any given piece of rough.
Maybe it's a marquise, heart shape or even horse head. Maybe it's a stone with an open culet

Of course there's a lot of badly cut diamonds out there but the reasons are rarely so simplistic.
About the grading - that's just greed IMO
Sellers knowingly offering mis graded stones to unsuspecting consumers is bad stuff.

To sleep I usually put my mind in a place that relaxes me. I love to think about Jamaica

 

[AprilBaby]

Thank you all. Unfortunately hubby is very allergic to pets, so no warm kitty or puppy to comfort me. RD, the architecture example was great. But what about my other question, assuming a stone was GIA graded, can it really be a total dud?

 

[SirGuy]

Hi, April. First, I'm sorry to hear about your insomnia. I've been there and it's rough!

Regarding whether a GIA stone can be a dud, sure it can. There are stones sent to GIA that get poor grades ("good" cut and such). Even if it's a "triple excellent" for cut, polish, and symmetry, it's important to look further.

I'm going to quote myself from an earlier thread where someone had a similar question.

As far as GIA "triple excellent" goes: I like that you're considering that as a minimum. However, GIA uses a proportion-based rounding for cut grades, and the "triple excellent" score covers a fairly big range. Some are good and some are low on that range and actually mediocre performers.

A reason for this is that because the score allows a crown angle and a pavilion angle to both be rounded (remember that there are lots of these facets involved, not just two!) and still get an excellent score if both are within an ideal range, even if they don't necessarily complement each other. This has allowed cutters to make what we call "steep/deep" combo stones (crown and pavilion angle) that retain weight (more money from rough) while still getting a grade that, on the surface, looks good to potential consumers.

AGS (the other preferred lab) uses 3D ray tracing of all 57 facets to develop a map of the stone and assign a cut score based on its overall light performance, polish, and symmetry. Each has to be a 0 (on a scale of 0-10) for the whole cut grade to be a 0. A stone with a 0 score for light performance, polish, and symmetry (and therefore overall cut) is known as an AGS0.

If you're going to aim for a GIA "ex/ex/ex" stone, it's critical to closely examine all of the numbers involved to ensure they complement each other, look at Ideal-Scope and ASET Images (as you've done) and also real magnified photographs.

I like to think of the four C's like sliders on a sound board. Dial up and down down. Each affects price and each is a compromise.

As Gypsy said, better cutting wastes more rough. Around some "magic numbers," cutters might be tempted to sacrifice cut to maintain weight. It can be easier to sell (or get more for) a 1.01 carat stone that's very well cut compared to a 0.96 carat that's superbly cut.

The best cutters and best vendors have "branded" lines where cut isn't sacrificed. You pay more, but you know why you're paying it.

 

[Karl_K]

Thank you all. Unfortunately hubby is very allergic to pets, so no warm kitty or puppy to comfort me. RD, the architecture example was great. But what about my other question, assuming a stone was GIA graded, can it really be a total dud?

There are some combos that could potentially get gia EX that are total duds.

 

[Karl_K]

As Gypsy said, better cutting wastes more rough. Around some "magic numbers," cutters might be tempted to sacrifice cut to maintain weight. It can be easier to sell (or get more for) a 1.01 carat stone that's very well cut compared to a 0.96 carat that's superbly cut.

That is what it comes down to.
Rough is sold based on potential of the polished from it.
If you have a bit of rough that will cut:
GIA EX .95ct
AGS 0 .88ct
HRD EX 1.01ct
EGL top cut 1.05ct

Then you do a value assessment and see which sells for the most money.
Then you consider how long it will take to sell in your market at each level.
Balance that to your business preference.
Cut accordingly.

 

[WinkHPD]

Pardon my rambling; I have bad insomnia tonight. I'm laying here thinking about various questions that come up and here are a few I have:

1. If we all want the best cut stones regardless of shape, why do cutters produce poorly cut stones? Inexperience? Lack of knowledge?

2. So the cutter has a stone that's not going to make a good GIA/AGS candidate. It goes to Egl/IGI. What makes a good GIA candidate over the lower grading houses?

3. If the better stones go to GIA/AGS, technically, for the average person, will they really get a bad stone if they purchase a GIA graded stone? Didn't it already pass some sort of standard to go to GIA in the first place? Most people can't tell one diamond from another. Most of us are cut snobs so we care.

4. Anyone know how to get rid of insomnia?????

Primarily because so few of the buyers understand cut well enough to demand it. We vendors are incredibly spoiled here on Pricescope to be dealing with a universe of buyers who understand so much more about cutting than the average buyer.

For example, back in the day when I had a B&M store I proudly presented three lovely ovals to a client, very proud that I had found her some diamonds without the normal ugly bow tie.

She told me how disappointed she was, that she had heard I was a good honest jeweler, but here I was trying to sell her defective ovals that did not have the requisite bow ties. When I got over my shocked and stunned silence I asked her where she had gotten such a horrendous idea.

She had been looking at one of the schlock houses here in town who had told her how rare it was to find ovals with such well defined bow ties. Sadly, there are thousands and thousands of schlock houses whose "jewelers" (read poorly trained sales staff) know little to nothing about diamonds. Many times more than there are Jewelers who actually know and care what they are selling.

That is why the cutters of drek cut drek. It is cheaper to cut, it yield's more weight and it allows them to sell the goods (hmmm, since they are ugly, why can't we call them bads???) for less per carat while still making more money in total.

To finish my story: I told her to go home and call any three name brand jewelers in the valley and ask them if bow ties were good or bad since she clearly was never going to believe I was unbiased.

She came back a day later and said that two of them just laughed at her and the third took his time to explain what a bow tie was, a cutting defect. She apologized and bought one of the diamonds I showed her the day before.

It worked out this time, but only because the lie was so outrageous. I lost as many sales to that (series of expletives deleted) as I won. He and his staff were very good liars.

Wink

 

[AprilBaby]

Thank you all again for your answers!

 

[John P]

...assuming a stone was GIA graded, can it really be a total dud?

There are some combos that could potentially get gia EX that are total duds.

Yes and yes.

Here are some bookend-duds for you.

GIA Excellent D IF ... "Save 1.50 by any means possible!"
Result = Sweet 41.8, 34.5 that leaks like a sieve (HCA 6.0), faces up like a 1.38.- under bright lights (and ??? in low lights).
Ooh. A D-IF WIN! (not)

GIA Poor E VVS2 ... Save 1.00 by any means possible!
Result = Pancake diamond with bizarre numbers appearing in unusual places (love the 5.5% CH).
No need to ship this one. Just chuck it, and it'll skip-skip-skip right across the ocean.

I included GIA numbers for any who want to check out the PDFs. Pretty illuminating.

 

[Rockdiamond]

April, you bring up a great point about GIA.
Pretty much everyone reading this understands that by going to a lesser lab, you will most likely be buying a misgraded diamond.
From this we can to deduce that by buying a stone graded by GIA, you will be getting in accurately graded diamond, and a vast majority of cases.
But – that does not mean it will be a desirable diamond, or well cut diamond.
I suppose that we could look at this as the opposite of the EGL grading scam. If the seller has stones graded by GIA and knows they are not well cut, he could use the fact that they are GIA graded to sell them.

It's important to remember that the discussion would be different if we're considering round diamonds, or fancy shaped diamonds.
For example, when I am looking to buy less expensive cushion shaped diamonds, I will look through cutters EGL graded diamonds.
There are many cases of warm colored diamonds, in fancy shapes, that would be submitted to EGL specifically for getting a better color and clarity.
Generally speaking I cannot use the same strategy for buying inexpensive round diamonds.
The reason is the value that the GIA cut grade adds. Yes, we can point to examples that are dogs, but the vast majority will be considered well cut diamonds.

This also affects the aspect of cutting. Karrl's example of how much weight you would lose going from perfectly cut to badly cut round does not apply to oddly shaped rough that would not cut to round diamonds anyway.

I can again point to the example of Horsehead diamonds. There is a great difference between a well cut horsehead, and a poorly cut Horsehead. However, even the best cut Horsehead diamond will not compare statistically, or in brilliance measurements, with a round brilliant cut well cut diamond.
This is not due to any bad reason – in fact it shows creativity on the part of a cutter who figured out how to use an oddly shaped rough to come up with something that's desirable to many people

 

[drk14]

2. So the cutter has a stone that's not going to make a good GIA/AGS candidate. It goes to Egl/IGI. What makes a good GIA candidate over the lower grading houses?

All great questions, and the answers have been illuminating. I'm going to ask a follow-up question to Question #2, however:

Is the implicit assumption behind this question actually true? What I mean is, is it true that cutters always send their higher-quality cuts to GIA or AGS for grading, and that a lab report from any other lab automatically implies the diamond has an inferior cut? Or conversely, if one is willing and able to look through and critically evaluate a lot of diamonds, is it possible to find a hidden "gem" (pun intended ) among the diamonds certified by "lesser" labs (or even uncertified diamonds)?

 

[Karl_K]

I can again point to the example of Horsehead diamonds. There is a great difference between a well cut horsehead, and a poorly cut Horsehead. However, even the best cut Horsehead diamond will not compare statistically, or in brilliance measurements, with a round brilliant cut well cut diamond.
This is not due to any bad reason – in fact it shows creativity on the part of a cutter who figured out how to use an oddly shaped rough to come up with something that's desirable to many people

Horsehead diamonds are kewl. I want one someday.
I view them as art more than something I would hold to the same standards as an RB.
I would judge them by how well they look like a horsehead than anything else.
I have seen 2 of them in person one was awesome you could almost feel the horses spirit captured in it.
The other was a lump of carbon.
The lump of carbon might have had a better ASET image and it would not have mattered.

 

[Karl_K]

2. So the cutter has a stone that's not going to make a good GIA/AGS candidate. It goes to Egl/IGI. What makes a good GIA candidate over the lower grading houses?

All great questions, and the answers have been illuminating. I'm going to ask a follow-up question to Question #2, however:

Is the implicit assumption behind this question actually true? What I mean is, is it true that cutters always send their higher-quality cuts to GIA or AGS for grading, and that a lab report from any other lab automatically implies the diamond has an inferior cut? Or conversely, if one is willing and able to look through and critically evaluate a lot of diamonds, is it possible to find a hidden "gem" (pun intended ) among the diamonds certified by "lesser" labs (or even uncertified diamonds)?

There are exceptions but you would be more likely to find reasonably well cut diamonds that are GIA L that were sent to EGL for a J grade or GIA I1 sent to EGL for a si2-3 and some cases si1 grade.
Higher color or clarity diamonds sell at a higher premium with gia/ags reports so are more likely to have other issues as to why they were sent to igi/egl.
The exceptions would be some companies that buy diamonds in bulk and send them all to igi/egl, like the big chains sometimes do.
IGI outside the US is better than the US IGI so that will change some what outside the US.

 

[SirGuy]

John, thanks for the two "bookend" examples. They are extremely illustrative of maintaining weight at the expense of cut. Chunky girdles and everything. It's a good image to use for demonstrations in a discussion like this.

 

[John P]

John, thanks for the two "bookend" examples. They are extremely illustrative of maintaining weight at the expense of cut. Chunky girdles and everything. It's a good image to use for demonstrations in a discussion like this.

My pleasure SirGuy. In this case I believe a picture (or proportions-graphic) is worth 1000 words!

Adding to Karl's comments... No. A diamond of premiere cut-quality will not be "automatically" sent somewhere. And neither will a diamond of dubious cut-quality. Let's leave DEF VVS+ out of the conversation for a moment... This isn't just about diamond X. It's also about markets. Expectations in a target-market can be every-bit as important to selling a diamond as the diamond itself.

1. Let's say diamond X is a round 1.00 J SI2 Ideal with perfect H&A by strict standards.

If I'm a cut-focused internet seller in the USA an AGSL report suits my market
If I'm a volume internet seller in the USA an AGSL or GIA report suits my market
If I'm an upscale showroom dealer in the USA a GIA report suits my market
If I'm a strip mall cash-for-gold discount dealer in the USA an EGL report (upgrading it to H SI1) suits my market
If I'm a seller in Asia I may have both GIA and IGI HK H&A reports, since Chinese consumers are accustomed to dual-reports for single diamonds). Or possibly NGTC (the national Chinese lab) and some other Western report (GIA, IGI, HRD)

Remember this is about the same diamond. Different reports accommodate different market expectations and familiarity.

Now let's put DEF VVS+ back INTO the conversation, along with mediocre cut.

2. Let's say diamond X is a round 2.00 D VVS1 VG by strict standards

If I'm a cut-focused internet seller in the USA I'll only list it virtually with the (likely) GIA, if I even list it.
If I'm a volume internet seller in the USA I'll list it with the GIA, but I'm not buying it for my signature line.
If I'm an upscale showroom dealer in the USA a GIA report is the way to go. Show it under bright lights.
If I'm a strip mall cash-for-gold discount dealer in the USA I won't sell it (too much $$$$)...
Instead, I'll present en EGL D VVS for 25% less and claim it's just as good.
If I'm a seller in Asia I'll get NGTC and GIA reports, but the VG is a distraction so I may cooperate with someone also listing it in the USA market.

A true collection-category diamond (DEF VVS+) of size especially, is likely to have GIA paper if it's not well cut. Just look at the two examples in the graphic I posted: You have D IF and E VVS2, both with serious reductions in quality due to cut (EX for the 1.50 notwithstanding). In these cases the producers are hoping any discounts needed for cut issues will be overcome by GIA's acknowledgment of collection color & clarity.

There is little chance that the 1.50 and 1.00 from the graphic above will ever move in a market that is focused on cut-quality. But someone who wants to claim 1.50 D IF can buy this alleged "Excellent" for a pretty serious discount from others of that weight. And, while I have no idea who would buy the pancake E VVS2 it does have a collection-category report from GIA... I just hope someone decides (please) to put it back on the polishing wheel and release the amazing, astonishing 0.53 E VVS2 top performer that's hiding inside

 

[Gypsy]

She had been looking at one of the schlock houses here in town who had told her how rare it was to find ovals with such well defined bow ties. Sadly, there are thousands and thousands of schlock houses whose "jewelers" (read poorly trained sales staff) know little to nothing about diamonds. Many times more than there are Jewelers who actually know and care what they are selling.

That is why the cutters of drek cut drek. It is cheaper to cut, it yield's more weight and it allows them to sell the goods (hmmm, since they are ugly, why can't we call them bads???) for less per carat while still making more money in total.

To finish my story: I told her to go home and call any three name brand jewelers in the valley and ask them if bow ties were good or bad since she clearly was never going to believe I was unbiased.

She came back a day later and said that two of them just laughed at her and the third took his time to explain what a bow tie was, a cutting defect. She apologized and bought one of the diamonds I showed her the day before.

It worked out this time, but only because the lie was so outrageous. I lost as many sales to that (series of expletives deleted) as I won. He and his staff were very good liars.

Wink

OMG. That's a priceless story.

Wink you have the greatest anecdotes. You have felt like this: quite often.

 

[WinkHPD]

She had been looking at one of the schlock houses here in town who had told her how rare it was to find ovals with such well defined bow ties. Sadly, there are thousands and thousands of schlock houses whose "jewelers" (read poorly trained sales staff) know little to nothing about diamonds. Many times more than there are Jewelers who actually know and care what they are selling.

That is why the cutters of drek cut drek. It is cheaper to cut, it yield's more weight and it allows them to sell the goods (hmmm, since they are ugly, why can't we call them bads???) for less per carat while still making more money in total.

To finish my story: I told her to go home and call any three name brand jewelers in the valley and ask them if bow ties were good or bad since she clearly was never going to believe I was unbiased.

She came back a day later and said that two of them just laughed at her and the third took his time to explain what a bow tie was, a cutting defect. She apologized and bought one of the diamonds I showed her the day before.

It worked out this time, but only because the lie was so outrageous. I lost as many sales to that (series of expletives deleted) as I won. He and his staff were very good liars.

Wink

OMG. That's a priceless story.

Wink you have the greatest anecdotes. You have felt like this: quite often.

LOL, yes I have. I am sure that all of the vendors here have those stories. Some of them are indeed priceless, some tragic. All are the result of the years that we have devoted to the profession that we love.

Somehow, the older I get the more of them I remember. I can tell you of con artists and their attempted cons, inside thefts that break my heart, stupid crooks that we caught and still, I LOVE this business. I have dealt with thousands of wonderful people over the years and each year I meet new ones. I am even now starting to deal with the GRAND CHILDREN of some of my earliest clients who are now getting ready to themselves get married. So yes, I have felt like quite often, but much more often I feel like .

I got an email from a client just last week that told me about his wonderful engagement trip and the surprise engagement event he planned and carried off. He had me laughing and by the end tears were "leaking" from my eyes as I reveled in his joy and the fact that I had been a part of her joy. The preponderance of such good clients far out weigh the efforts of the cons and crooks to bring me down.

See, a mere comment and here I am rambling on again. Thank you for your kindness in liking my stories!

Wink

 

[Andelain]

Here are some bookend-duds for you.

GIA

Got an IS or ASET on that bottom one?

 

[John P]

Got an IS or ASET on that bottom one?

Andelain: It's not in my possession - although I might buy it, given a budget for head-shaking oddities.

Here are ASET simulations for both. These wire-frames look symmetrical because they are "perfectly imagined" wire-frames, created by using single (averaged/rounded) data points for multiple measurements. Actual ASET images would be more chaotic, as they'd show real-life variations and distortions in the patterning. With that said, the basic angular spectrum coding in these sims is reliable.

 

[Andelain]

OMG, that's bad!

Think Jon may have you beat for worst ASET, though. Take a peek at this one! [URL='https://www.pricescope.com/community/threads/rhino-i-just-got-to-ask.198668/']https://www.pricescope.com/community/threads/rhino-i-just-got-to-ask.198668/[/URL]

 

[John P]

Bless its heart.

Worst-ASET-owner is a title I'll gladly yield to someone else I do have a thick re-cut folder full of contenders, though, and it occurs to me that I can show how the "perfectly imagined" wire-frame can make a simulation seem better than the actual.

I just entered the basic data for this off-chart steep-deep I acquired for re-cut. Here's the simulated ASET.


And here's the actual ASET, taken before it was sent it to Antwerp.


While the general-sim is close enough for us to get the gist, the actual image has variances outside of the given averages which cause increased light loss, especially at the girdle.

Of course... Now I want to call in the pancake diamond from above for curiosity's sake! Crikey.