For the experts (play nice)- Feathers and cavities-CLARITY

[SparklySoprano]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Thank you so much, Experts, for chiming in on this. I definitely want to spend some more time reading through and digesting. But, I did also wonder about the plotting colors, green vs red, and why wouldn't green be used if the surface was reached? And is a needle considered any worse than a feather?

 

[Rhino]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Thank you so much, Experts, for chiming in on this. I definitely want to spend some more time reading through and digesting. But, I did also wonder about the plotting colors, green vs red, and why wouldn't green be used if the surface was reached? And is a needle considered any worse than a feather?

Hi SparklyS,

Nope. A needle is simply an elongated crystal that is totally contained within the diamond. No worries about those except perhaps I'd wonder what color the needle is as well as its size and position.

Kind regards,
Rhino

 

[littleweight]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Rhino and TL:

Great info posted in this thread. Its a great read up! I purchased my diamond from a vendor here. I am 110% satisfied with it and love it. Id love to get your personal feedback via AGS report if you don't mind. Hearing your feedback would be great

 

[Texas Leaguer]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Rhino and TL:

Great info posted in this thread. Its a great read up! I purchased my diamond from a vendor here. I am 110% satisfied with it and love it. Id love to get your personal feedback via AGS report if you don't mind. Hearing your feedback would be great

I will defer to Rhino on the overall assessment as I am not the expert on cushions that he is. I will say that judging from the ASET it must be a very bright diamond, and the fact that it gets AGS0 light performance would indicate that it has outstanding fire and sparkle as well. Color and clarity are excellent. The fact that polish and meet point symmetry do not quite rise to Ideal will not be detrimental to any appreciable degree.

I bet it's a real fine rock!

 

[Rhino]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Rhino and TL:

Great info posted in this thread. Its a great read up! I purchased my diamond from a vendor here. I am 110% satisfied with it and love it. Id love to get your personal feedback via AGS report if you don't mind. Hearing your feedback would be great

When it comes to the issues we are discussing in this thread none of this can be determined from a lab report. A live examination with the proper gemological equipment is necessary as we've turned down many diamonds with great ASET's due to the gemological issues raised here.

When it comes to optics and computer generated ASET's on AGS Reports (or even photography) I'll never generally comment unless we can confirm visually. The preliminaries look good but not conclusive.

Regards,
Rhino

 

[littleweight]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Thank you both for the input!

 

[Garry H (Cut Nut)]

Re: For the experts (play nice)- Feathers and cavities-CLARI

I have not read all this, but simply, a feather is a crack that is a crack as in common language - it breaks the surface along the green line.
Inclusions (i.e. inside a diamond) are shown in red.
The definitions of crystal needle and albatross are meaningless to me. The only other catagory that comes to mind is twinning, and that refers to diamond inside diamond growing possibly in alternative directions.

 

[pyramid]

Re: For the experts (play nice)- Feathers and cavities-CLARI

AGS feathers are red and not green though so are they inclusion or crack?

 

[Rockdiamond]

Re: For the experts (play nice)- Feathers and cavities-CLARI

From my perspective, the confusion surrounding the terminology hurts consumers.
Here's why:
Do feathers reach the surface as a rule?
Not in my experience looking at diamonds and GIA reports.
Again this is all "grey area" due to GIA conflicting literature.

Crack is bad- and it's really unqualified "bad".
If I didn't understand what a feather looks like and how it affects beauty and durability, I'd skip any "cracked diamond"


SO- If one is shopping for a given diamond, and rules out GIA identified "Feathers" due to the "cracked" or "Open" connotation they may indeed eliminate the best candidate to meet their needs.
I can't recall seeing a VS or better graded stone possessing a feather that was problematic.
Even down to SI2.
Sometimes a feather is far preferable to a stone with a crystal.

 

[pyramid]

Re: For the experts (play nice)- Feathers and cavities-CLARI

I have often wondered about how clarity is portrayed on the internet. Labs say durability is relevant in I1 i2 categories, with I sometimes called Included and sometimes called Imperfect. Clarity comes from the word clear but this has nothing to do with durability. I wonder if it is just the internet education material which scares customers so they will get diamonds with grading reports and use services of appraisers. Offline no one ever speaks of this.

 

[Diamond_Hawk]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Offline no one ever speaks of this.

Pardon my confusion here, Pyramid - when you say "Offline no one ever speaks of this" do you mean brick and mortar stores do not, in your experience, speak about clarity? Or do you mean you have not heard, other than on the internet, that clarity grades can gives clues about durability?

I have often wondered about how clarity is portrayed on the internet.

Do you find clarity is portrayed differently in B&M stores than on the internet? While I am sure different dealers have differing approaches, definitions of clarity are - in my experience - fairly standardized due, in large part, to the free availability of information in the trade and on the internet.

I wonder if it is just the internet education material

Is there educational material that is found only on the internet? Most of the citations regarding feathers in this thread have come from published GIA literature (which may or may not also be available online).

which scares customers so they will get diamonds with grading reports and use services of appraisers.

Are you advocating customers should seek diamonds without grading reports?

Any clarification would be helpful - thanks!

 

[pyramid]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Hi diamond hawk

I meant all jewellers in bricks and mortar stores in the UK I have been too only refer to how clear a stone is and never mention the word crack like it is mentioned on diamond forums and on some websites which have sprung up because of forums. When asked about feathers they just say all diamonds have inclusions and go onto say about better grades having less but never speak about cracks or durability just clarity as in more or less clear. I do agree with diamond reports but they are not widely used here. I asked a few years back in an expensive jeweller about getting a GIA report once and was told they could get me an HRD report which was the equivalent to what America uses. I notice he now has GIA certificates but they are alongside IGI. When I speak to friends or colleagues they couldn't care less about the 4 C's and only buy with their eyes. I asked many years ago about feathers on here and got good replies from Garry Holloway and Rockdoc and notice other new people coming on the forums worried in the same way. I remember being told once that a diamond is a solid like a ball and shouldn't be thought of like a pane of glass where a crack could go through the whole width, that was Juan Van Graff who posted that on the other forum and he was a rocket scientist.

Have many people here heard of diamond clarity referred to as cracks offline? I have spent a long time reading about diamonds but a lot of times diamond grading of clarity reminds me of a forum I happened on onetime where they were talking about graphic equalizers which were very expensive and most people could not hear the difference or like wine tasting. It is not real world diamond clarity talk in my opinion.

I believe the information I read before the internet referred to durability only being a worry at I1 and down and have even seen some vendors here say that.

The GIA literature does give dictionary and grading definitions about feather being a fracture etc which is fact but they do not tell people to avoid diamonds where a feather breaks the surface nor have photos like for example sites like Nice Ice - telling people they reject diamonds with SI1 feathers at the girdle, that is not coming from GIA. This takes the pleasure or romance out of diamond shopping. Look at all these old cut diamonds being bought for their pattern - what was the education in clarity like back then. In real life before the internet people would buy the diamond unless the jeweller found it fallen apart or with a large chip I would imagine. Clarity would have been about clearness not durability for shoppers the unstable diamonds would have been dealt with by the cutter or jeweller if they got that far even.

 

[Texas Leaguer]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Hi diamond hawk

I meant all jewellers in bricks and mortar stores in the UK I have been too only refer to how clear a stone is and never mention the word crack like it is mentioned on diamond forums and on some websites which have sprung up because of forums. When asked about feathers they just say all diamonds have inclusions and go onto say about better grades having less but never speak about cracks or durability just clarity as in more or less clear. I do agree with diamond reports but they are not widely used here. I asked a few years back in an expensive jeweller about getting a GIA report once and was told they could get me an HRD report which was the equivalent to what America uses. I notice he now has GIA certificates but they are alongside IGI. When I speak to friends or colleagues they couldn't care less about the 4 C's and only buy with their eyes. I asked many years ago about feathers on here and got good replies from Garry Holloway and Rockdoc and notice other new people coming on the forums worried in the same way. I remember being told once that a diamond is a solid like a ball and shouldn't be thought of like a pane of glass where a crack could go through the whole width, that was Juan Van Graff who posted that on the other forum and he was a rocket scientist.

Have many people here heard of diamond clarity referred to as cracks offline? I have spent a long time reading about diamonds but a lot of times diamond grading of clarity reminds me of a forum I happened on onetime where they were talking about graphic equalizers which were very expensive and most people could not hear the difference or like wine tasting. It is not real world diamond clarity talk in my opinion.

I believe the information I read before the internet referred to durability only being a worry at I1 and down and have even seen some vendors here say that.

My sense is that the last statement is generally true with regard to rounds (and other shapes without points). However, a diamond graded Si2 with only a large feather extending to the girdle would be something I would want to take a hard look at from a durability standpoint because it could be a borderline call.

It is good to know about different clarity features from a standpoint of what they might represent in terms of eye-visible inclusions and transparency, but basically the plotting and inclusion type designations are done for the purpose of positively identifying the diamond. Significant durability issues should not come into play except in the lower clarity grades, no matter what type of inclusion happens to be present.

As with everything, there are bound to be exceptions to the rule - clarity grading is done by humans after all!

 

[pyramid]

Re: For the experts (play nice)- Feathers and cavities-CLARI

You are right diamond hawk it is free education and also maybe that people want perfection more. However now it has been said that feathers which are internal are plotted as crystals and when they reach the surface they are feathers, then no one will be able to avoid feathers unless they are examined by a microscope by a gemmologist? Why do GIA not have them plotted in green if they say all feathers reach the surface because it is usually indented nasturals and cavities we see in green. This was mentioned by Jon at GOG too.

 

[Rockdiamond]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Pyramid- you've raised some AMAZING points.
I spend a massive amount of time personally explaining clarity grading to consumers.
The information available online is conflicting at best.
One thing we are in the middle of nowadays- information overload.
If there's too many things published- it makes it very difficult to figure out which is relevant, and menaingful.
That in itself is a problem.
In the case of clarity grading, it makes it far easier to convince someone that they "need" to by a VS to avoid some really nasty stuff.
And it's simply not the case.
It's also not in consumer's best interest forcing them to eliminate SI graded stones as a rule.
Of course some people will not want to buy a stone with a carbon crystal, even if they can't see it.
Nothing wrong with that.
But if a consumer believes a VS stone is sparklier than an SI automatically, they are misinformed- and I can tell you from experience, that is exactly what many consumers believe.


Of course any SI clarity diamond must be carefully examined to make sure it's desirable, and has no problematic imperfections.
But then again, so must every Internally Flawless be examined

 

[Karl_K]

Re: For the experts (play nice)- Feathers and cavities-CLARI

In my opinion there is no hard and fast rules that cover durability and all shapes.
For example in my opinion any inclusion in the corners of a princess cut are a potential durability issue.
That includes vs1 and maybe even vvs2.
Where the same inclusion away from the corners is no issue.
It is a matter of location and a vulnerable spot in the diamond.
I don't like cavities on the crown or girdle in all cuts.
I don't like open feathers open to the top of the stone in all cuts.
I don't like a crystal that reaches the surface and vulnerable to being knocked out.(sometimes but not always plotted as knots) But not all of them are vulnerable to being knocked out.
But that is just my opinion some will agree some wont.

On the other hand a family member had a i1/i2 princess cut with an eye visible feather across the stone.
The ring was dropped and the diamond shattered, the part with the feather looked brand new but the other almost 1/2 of the stone was in pieces.

So you can never tell which is why insurance is mandatory.
No diamond is immune to breaking on the other hand if they often broke insurance would be much more expensive than it is now.

 

[Rockdiamond]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Hi Karl,
If you think about the actual physical size of a VVS2 or VS1 imperfection- then consider the stresses a princess cut diamond has already undergone on the wheel.....and also taking into account your story about a shattered stone not even shattering on the imperfection ( I agree that's far more common than a break on the imperfection) ) I have to agree your preference is important.
But from a practical standpoint, there's virtually no possibility of a durability issue whatsoever on a VS1, or VVS2 princess cut.

 

[Diamond_Hawk]

Re: For the experts (play nice)- Feathers and cavities-CLARI

I do not think there is much disagreement on the surface here, but when we get under the surface there is some distortion causing a lack of clarity in the definitions of the terminology being used (see what i did there?).

Put succinctly, we will find that the clarity category covers “natural characteristics” which are categorized as blemishes (surface) and inclusions (internal). When taken together, those characteristics determine how “clear” the diamond is (transparency/pique) as well as how “durable” the diamond is (breaks and structural distortion).

Obviously, a diamond which is I1 may not have durability issues. A diamond which is I2 will *either* have severe issues with “clear” OR with “durability.” A diamond falling into I3 typically has issues with both clearness and durability.

I will also agree that this type of information is more present - and more freely available - on the internet than in the mall.

 

[Karl_K]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Hi Karl,
If you think about the actual physical size of a VVS2 or VS1 imperfection- then consider the stresses a princess cut diamond has already undergone on the wheel.....and also taking into account your story about a shattered stone not even shattering on the imperfection ( I agree that's far more common than a break on the imperfection) ) I have to agree your preference is important.
But from a practical standpoint, there's virtually no possibility of a durability issue whatsoever on a VS1, or VVS2 princess cut.

You would ok with a vs1 feather right in the corner of a princess cut?

 

[Rockdiamond]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Hi Karl,
If you think about the actual physical size of a VVS2 or VS1 imperfection- then consider the stresses a princess cut diamond has already undergone on the wheel.....and also taking into account your story about a shattered stone not even shattering on the imperfection ( I agree that's far more common than a break on the imperfection) ) I have to agree your preference is important.
But from a practical standpoint, there's virtually no possibility of a durability issue whatsoever on a VS1, or VVS2 princess cut.

You would ok with a vs1 feather right in the corner of a princess cut?

Karl- I've never seen a VS1 sized imperfection that would pose a durability issue, on any diamond.
Again, remember the physical size of a VS1 imperfection-.05 mm?
Really tiny in real life.

I do not think there is much disagreement on the surface here, but when we get under the surface there is some distortion causing a lack of clarity in the definitions of the terminology being used (see what i did there?).

Put succinctly, we will find that the clarity category covers “natural characteristics” which are categorized as blemishes (surface) and inclusions (internal). When taken together, those characteristics determine how “clear” the diamond is (transparency/pique) as well as how “durable” the diamond is (breaks and structural distortion).

Obviously, a diamond which is I1 may not have durability issues. A diamond which is I2 will *either* have severe issues with “clear” OR with “durability.” A diamond falling into I3 typically has issues with both clearness and durability.

I will also agree that this type of information is more present - and more freely available - on the internet than in the mall.

In my experience, none of this is "obvious" to consumers.
I would not use the word "clear" in this context.
IMO it clouds the issue ( my turn for a pun)

 

[pyramid]

Re: For the experts (play nice)- Feathers and cavities-CLARI

We don't have mall's in the UK but they are called shopping centres but the jewellers I was speaking off were family owned since 1940s and one has its store in a city main street and the other has a double store on a road off the city main street. They don't mention any of the C's on the certificates unless you ask, they sell diamonds into the thousands of pounds up to 45,000 and there was a beautiful cushion cut sapphire for £19,000. I suppose it is only good to be careful and know about what you're buying but no one seems to discuss it in the way they discuss the power capabilities of a new car they were buying. Most don't know clarity and colour exists over here and cut to the public means shape only e.g. pear or square or oval.

 

[Diamond_Hawk]

Re: For the experts (play nice)- Feathers and cavities-CLARI

In my experience, none of this is "obvious" to consumers.

Agreed - offered in the spirit of those participating in the conversation.

I would not use the word "clear" in this context.
IMO it clouds the issue ( my turn for a pun)

Understood


This was in response to the same terminology used by Pyramid above:

by Pyramid
I meant all jewellers in bricks and mortar stores in the UK I have been too only refer to how clear a stone is...

 

[pyramid]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Yes natural characteristics of the diamond have nothing to do with the word clear. The old colour gradings where they used the word 'water' would sound more like clear and clarity, the lack of natural characteristics make it clearer but durability is strength not see through.

 

[pyramid]

Re: For the experts (play nice)- Feathers and cavities-CLARI

In my experience, none of this is "obvious" to consumers.

Agreed - offered in the spirit of those participating in the conversation.

I would not use the word "clear" in this context.
IMO it clouds the issue ( my turn for a pun)

Understood


This was in response to the same terminology used by Pyramid above:

by Pyramid
I meant all jewellers in bricks and mortar stores in the UK I have been too only refer to how clear a stone is...

Well how can it be obvious to us lowly customers, or is it that this thread is only for experts as the title says. I think it is obvious in the real world but here we are taught to be scared buying diamonds so we ask questions, get hauled in and buy from the internet. I mean if an I1 would obviously have no durability issues then why are new buyers told to ask vendors to look at SI clarity stones with grading reports from GIA to make sure the feather does not break the surface (which they all do according to GIA). An SI clarity is OBVIOUSLY higher than I1 which you say have no issues of durability. There again only an internet expert can determine that though.

 

[Diamond_Hawk]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Well how can it be obvious to us lowly customers, or is it that this thread is only for experts as the title says.

Perhaps I can answer your questions. I saw no one call customers lowly, nor even imply that was the case.

My terminology was "Agreed - offered in the spirit of those participating in the conversation." - As you are a participant, I qualified all of us together. My statement would have stood on it's own merits with or without the qualifier in front.

I think it is on books on in the real world but here we are taught to be scared buying diamonds so we ask questions, get hauled in and buy from the internet.

I am confused by the terminology 'real world' - if, by that term, you mean B&M stores this seems to contradict your earlier implication that B&M stores do not, in your experience, try to confuse customers with too much information so they will be more at ease. And, as I represent (as do many people on this forum), an internet diamond-seller I hate that anyone would feel they were "hauled in" to the internet - implying some type of trickery or trap. It is/was my experience both as a consumer and now as a representative that the free exchange of ideas on a forum such as this one is exactly what many people are looking and hoping for before making a diamond purchase.

You do not have to look far to find physicists, engineers, teachers and consumers from all walks of life (none of them lowly) fascinated by and reveling in the information available on PriceScope. I submit that it is the PriceScope community and the internet-at-large that has helped drive numerous large diamond sellers to make Ideal-Scope and ASET images available to consumers. It is now easy for someone to know what they can expect from a GIA or HRD or AGS or IGI graded diamond based upon the information they can find here. It is fascinating to follow the threads where ETAs and Yaw are discussed relative to lower girdle facets or the expected fire vs. brightness two diamonds of slightly different angle combinations may provide.

It is equally satisfying to look at the incredible posts in "Show me the Bling" and hear the heart-warming stories that people share about their engagements or recent purchases. It is great to follow a thread that lasts for pages and pages about colored diamonds or specialty jewelry. These threads are popular because it is all information people want. If people do not want to read it, they simply skip it. There is no harm done by presenting information, is there? Isn't it good that people can read and participate in a thread with others who are discussing the details of a particular cut, the differences in color or even concern for durability based on a clarity grade...?

If you choose to use PriceScope and other internet resources, aren't you more likely to find useful information here than in your corner store? If you want to, that is.

I mean if an I1 would obviously have no durability issues then why are new buyers told to ask vendors to look at SI clarity stones with grading reports from GIA to make sure the feather does not break the surface (which they all do according to GIA). An SI clarity is OBVIOUSLY higher than I1 which you say have no issues of durability. There again only an internet expert can determine that though.

I think you misread my statement. I said "Obviously, a diamond which is I1 may not have durability issues"... it MAY NOT have durability issues - OR - it MAY have durability issues, right? By stating it in this way, it actually IS obvious. An I1 - obviously - may have durability issues, or -obviously- it may not.

Was it phrased clumsily? Perhaps. But, it is demonstrably true that ANY diamond, of ANY clarity grade may or may not have durability issues...the extent of those issues, now THAT is what the discussion is all about.

 

[Rockdiamond]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Pryamid,
I share your frustration.
Its all kind of confusing because it's been over-complicated.
A lot of times microscopic issues get overblown.
Based on a lot of online information ( not here), it's reasonable to assume that all SI2 diamonds suck.
I love SI2 diamonds. The right SI2 diamonds.
Even better, please give me an I1 - the eye clean variety.
Look at the difference in price between G/VS1 and G/SI2

The key point I stress in advising about clarity is that the GIA grade is base on presence of imperfection, as opposed to visibility of imperfection.
Here's one of a million different grading scenarios- say we have a GIA graded VS2 with a single identified feather.
If this feather in exactly the right spot, you will be able to see it with the naked eye - especially in stones 1ct and up.
But that's a rare case in GIA graded VS2 Round Diamonds.
If it's tucked away deep inside, or in a corner- you'd never be able to see it with the naked eye.
So we have eye clean VS2's and non eye clean VS2's

Now let's add another VS2 sized imperfection to the eye clean VS2, and now we've now got an SI1.
If this second VS2 sized imperfection is also in a place where it blends in, you've still got an eye clean diamond.
Add a third imperfection, and we can get to SI2 diamond where all the clarity characteristics are minor unto themselves. This results in a totally eye clean diamond with virtually no perceived diminution of brilliance- especially if it's a super well cut stone.

Another SI2 might have only one imperfection- but a much stronger one.
Those are generally the SI2's that have easily visible imperfections.

If I'm shopping for myself, I look for the kind of eye clean Si2 diamond I described.
I need a big diamond, I have a size 14.5 ring finger
Remember, as the stone gets larger the actual dollar savings truly add up.

 

[diagem]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Reading the confusion around the durability issues.
Today a colleague showed me a parcel of low (full of inclusions) quality rough he has.
The stones interior were full of all the clarity characteristics any lab could identify..., feathers (cracks) from edge to edge and much more.
A few rocks fell on the marble floor and guess what? Nothing happened.
Diamonds are the hardest substance on earth BUT at the same time can be extremely brittle.
I guess it's would be a matter of luck most of the time, but in extremely rare instances when only a soft hit in the “right place” (usually a weakness spot not necessarily due to an inclusion) can cause damage..., but according to my 30+ years of experience, it could potentially happen to a clean stone as much as it can happen in a I1-2-3 stone.

Now let me write out of experience as someone who used to cleave Diamonds (manually the old fashioned way) as part of my numerous apprenticeships in the beginning of my career.
I used to manually carve a tiny cleft on the external rough skin in a spot where I would plan on dividing the Diamond by a direct blow of a hammer.
The knife (which I insert in the cleft for the hit) had one crucial role in the process..., both sides of the knife must touch both inner-walls of the cleft in order to be able to split within a specific Diamond plane. If the end (thin part) of the knife would touch the inner thinnest part of the cleft then most probably nothing would have happened (seldom the split might change direction due to this wrong way of hitting) and I would have to fine tune the cleft for a better knife position for the next attempt. Only when both ends of the knife would touch in the right places in the cleft (as mentioned above), only then we would have a satisfactory splitting of the Diamond.

This just to show Diamonds are not that vulnerable.

There is an (unconfirmed) “story” on Joseph Asscher and the cleaving of the Cullinan Diamond (early 1900’s), story goes on saying when Joseph Asscher attempted his first blow at splitting the huge Diamond, the first blow was unsuccessful which caused Joseph Asscher to faint, nothing happened to the Cullinan until his second successful attempt.

 

[pyramid]

Re: For the experts (play nice)- Feathers and cavities-CLARI

I am sorry diamond hawk, I read what you wrote and took it the wrong way. There is also the point you made about the internet expanding our knowledge I just never thought of it that way. Rock diamond I like how you explain an SI1 diamond as perhaps containing 2 vs2 size inclusions, I just thought the inclusions all had to be si1 size, that is educational I wonder if other consumers never knew that either? Diagem that is a great post , from the horses mouth so to speak.

 

[Karl_K]

Re: For the experts (play nice)- Feathers and cavities-CLARI

I am sorry diamond hawk, I read what you wrote and took it the wrong way. There is also the point you made about the internet expanding our knowledge I just never thought of it that way. Rock diamond I like how you explain an SI1 diamond as perhaps containing 2 vs2 size inclusions, I just thought the inclusions all had to be si1 size, that is educational I wonder if other consumers never knew that either? Diagem that is a great post , from the horses mouth so to speak.

The problem is finding them particularly if your buying off a list.
They are often snagged up before they make the lists by dealers who have an inside track to buy before they are listed. Some of the PS dealers are big enough to do that so you will see them from time to time.
They will also in general sell at a premium at the wholesale and consumer level.
Some huge cutters use internal grading to separate such stones and have a separate pricing tier for them and dealers who buy them as soon as they pop up.