How important are HCA factor grades in assessing diamonds?

[diagem]

Re: How important are HCA factor grades in assessing diamond

Sadly, Yoram, you are right.
Karl how could WE better help poeole find the cream?

Saturate the market.

Wont help unless part of the education process explains heavier cost burden that comes with the cream (as CCL correctly mentioned above).

 

[Karl_K]

Re: How important are HCA factor grades in assessing diamond

Sadly, Yoram, you are right.
Karl how could WE better help poeole find the cream?

education and research
pro-sumers are the key
They are a vital resource that needs care attention and protection.
As you know I have been complaining about the protection part getting lax and them getting left hanging on stuff we taught them because it might offend a couple people in the trade.

 

[Rockdiamond]

Re: How important are HCA factor grades in assessing diamond

I think PS is doing a very good job by hosting discussions such as this one.
Although the study of how a diamond handles light is scientific in nature, evaluation of these studies is subjective- as opposed to scientific. This is not about trying not to insult anyone, it's a fact.
When it comes to diamonds, what one considers the "Cream" is subjective. When it comes to Light Performance, there is no accepted standard of what is "best". That's why many prefer the methodology of GIA's cut grade to AGS's
This type of discussion highlights the fact that not everyone prefers what is termed here to be "cream"- and I strongly believe that putting this into perspective is indeed very helpful for consumers.

 

[diagem]

Re: How important are HCA factor grades in assessing diamond

Although the study of how a diamond handles light is scientific in nature, evaluation of these studies is subjective- as opposed to scientific.

RD..., its not subjective..., dont mix beauty with LP.
LP can be objectively measured.
Beauty is subjective, something we all agree upon.

How are your experiments with your new Aset device going..., based on your writing I understand you still didnt see the light

Dont give up!

 

[Rockdiamond]

Re: How important are HCA factor grades in assessing diamond

Thanks for asking Yoram.
Based on my experience with it, I can not anticipate ever wanting to use the aset instead of looking at the diamond "naked eye" and with a loupe.
However we have started to add aset images to the site.


With regards to evaluating LP- I don't see how we can effectively prove that any given stone is "the best" in LP.
Although it might be possible to identify stones large dark zones, that might be more universally accepted as a shortfall, once we get to a certain plateau, how we interpret the way a diamond uses light is opinion.

 

[diagem]

Re: How important are HCA factor grades in assessing diamond

Thanks for asking Yoram.
Based on my experience with it, I can not anticipate ever wanting to use the aset instead of looking at the diamond "naked eye" and with a loupe.
However we have started to add aset images to the site.

No one would expect you to use Aset instead..., it is a tool that will/should help you better understand the optics especially when looping or observing a Diamond, your experience is still young but keep comparing what you see IRL vs Aset


With regards to evaluating LP- I don't see how we can effectively prove that any given stone is "the best" in LP.
Although it might be possible to identify stones large dark zones, that might be more universally accepted as a shortfall, once we get to a certain plateau, how we interpret the way a diamond uses light is opinion.

Again you are switching words of different meanings..., who said "best" or "interpret"? I said measure (big difference). You keep trying your best to move to the subjective side and I am trying to keep you focused on the objective part of the discussion.

 

[Rockdiamond]

Re: How important are HCA factor grades in assessing diamond

Let's agree that it's possible to measure how much light comes out of the diamond, in a given environment.
However if we do that, the result is NOT "Light Performance"- unless we move back to the subjective judgement.
We would be measuring "Light Return".
IN this context, the word "performance" is in the realm of interpretation. We all agree that 100% light return is something like a mirror, and not desired.

Further, the measurement of light return ( as AGS might do) uses certain givens that may not hold true to real life, or how the diamond is viewed.
For sure diamonds react differently the different lighting scenarios.

 

[Garry H (Cut Nut)]

Re: How important are HCA factor grades in assessing diamond

If anyone, including you david, wishes to truly come to grips with many of the issues being discussed, then here is some really definitve reading below:

Let's agree that it's possible to measure how much light comes out of the diamond, in a given environment.
However if we do that, the result is NOT "Light Performance"- unless we move back to the subjective judgement.
We would be measuring "Light Return".
IN this context, the word "performance" is in the realm of interpretation. We all agree that 100% light return is something like a mirror, and not desired.

Further, the measurement of light return ( as AGS might do) uses certain givens that may not hold true to real life, or how the diamond is viewed.
For sure diamonds react differently the different lighting scenarios.

David the Cut Group agree with some of these statements.
AGS has a digital anayltic approach which is some years behind the Russian work.
GIA did a human study, but rather poorly.

No one has done both.
We nearly made an agreement to do this with HRD (IMO have better scientific capacity thru their R&D facility, WTOCD, than either US lab).

Here is some of the basis of that:
http://www.gemology.ru/cut/english/conferens-article/2.htm
I deliberately linked to the middle of the article with2 graphic charts near the page bottom describing how a digital system can properely be linked to human judgement of beauty - WITH the capacity to provide information about variances in tatse for race, nationality, region and age demographics.

This longer presentation outlines the approach in more detail:
http://www.gemology.ru/cut/english/conferens-article/6.htm

General:
http://www.octonus.com/oct/projects/strategies.phtml



Here is some history including discussions of some errors in GIA's early work
http://www.gemology.ru/cut/english/grading1/index.htm

 

[diagem]

Re: How important are HCA factor grades in assessing diamond

Let's agree that it's possible to measure how much light comes out of the diamond, in a given environment.
However if we do that, the result is NOT "Light Performance"- unless we move back to the subjective judgement.
We would be measuring "Light Return".
IN this context, the word "performance" is in the realm of interpretation. We all agree that 100% light return is something like a mirror, and not desired.

Further, the measurement of light return ( as AGS might do) uses certain givens that may not hold true to real life, or how the diamond is viewed.
For sure diamonds react differently the different lighting scenarios.

Please dont start word games as its my weakness and you are going to make me work to hard.

The physical measuring of light return results in a few numbers that really doesnt mean much to me (and shouldnt to you either unless you wish to dive deep into the science), obviously the highest the better (I presume in a correct combination) but we all know we dont want a mirror on our finger .

I am looking more into the behaviour of the light return. Yes behaviour can be subjective but to be able to achieve the results a super precise cut can deliver you need to live in peace with the fact that light return can be objectively measured.

RD, I believe all Diamonds are potentially beautiful (even rough)...



So please stop preaching this tune as I and others already know and admitted beauty is subjective!

You keep voicing the "trade" at large (outside of PS) as reliable examples in your many discussions..., we are discussing issues 90%+ (I feel super safe with the + ) of the members of our trade/industry wouldnt even know is in existence. Its sad but true!

Well at least we know it did penetrate a bit as you yourself said you are starting to add Aset images to your products.

 

[risingsun]

Re: How important are HCA factor grades in assessing diamond

In the mental health field, we write progress notes about sessions with our clients. Some of us the "SOAP" format:

S=subjective impressions
O=factual observations
A=assessment based upon both S & O
P=plan for the next session/step

Why can't we look at diamonds from a similar perspective. There is a subjective element involved, but there is a scientific aspect to take into consideration, as well. We can make an assessment based upon both. We don't have to choose between them. Some of us may skew toward "O" and others toward "S," but trying to eliminate one or the other isn't reasonable. The science exists and is not simply someone's opinion. The subjective piece is, in fact, someone's opinion. Why are we still going on and on about this. It keeps us stuck in the same discussion, thread after thread. I would really like to see us move beyond this point.

 

[risingsun]

Re: How important are HCA factor grades in assessing diamond

^^^...some of us use...[because good grammar is my friend ]

 

[ChunkyCushionLover]

Re: How important are HCA factor grades in assessing diamond

In the mental health field, we write progress notes about sessions with our clients. Some of us the "SOAP" format:

S=subjective impressions
O=factual observations
A=assessment based upon both S & O
P=plan for the next session/step

Why can't we look at diamonds from a similar perspective. There is a subjective element involved, but there is a scientific aspect to take into consideration, as well. We can make an assessment based upon both. We don't have to choose between them. Some of us may skew toward "O" and others toward "S," but trying to eliminate one or the other isn't reasonable. The science exists and is not simply someone's opinion. The subjective piece is, in fact, someone's opinion. Why are we still going on and on about this. It keeps us stuck in the same discussion, thread after thread. I would really like to see us move beyond this point.

Risingsun,

The problem is this, there are far too many voices on this site who don't have the time or incentive to seperate objective from subjective. Doing so requires active study and overcoming a steep learning curve.

You have made better attempts at understanding than the average PS poster and it shows in some of your posts, but can you really seperate in this thread the subjective comments from objective ones or the subjective and objective elements of the GIAL and AGSL
grading systems?

If one doesn't understand the science or appreciate the robustness of the research of the AGSL foundations article than its far too easy to just say its wrong(provide negative example) or I don't trust it.

I can link the AGSL foundations article 1000 times in threads, it doesn't mean you or others will conscieniously read it or paraphrase its contents and ask relevant questions or make relevant challenges to its foundations. I did challenge the AGSL grading system and wrote and discussed by phone for hours with its founders.

RD and trade like him have a self serving attitude that resists change and moving forward. They are comfortable in the way they select diamonds and see no reason to change it. To support that comfort they claim everything is subjective, the entire system is subjective, diamond beauty and everything to do with it is subjective. Under such a loud and destructive voice I have no interest in highlighting the limitations of AGSL's system, I know many of them but it wastes my time to share them when noone appears to listen or understand.

Noone doing research needs to deal with that kind of Luddite and stubborn position, it doesn't educate anyone it only preaches to the lazy and uneducated. This position is allowed because it is partially or fully supported by those who don't understand the fine technical details and don't want to.

To the ones who truly understand the differences between the two systems, they have long left the discussion or are proposing another "black box" and this isn't helping either. Just not enough of that kind of voice is active on pricescope now, why should it be it isn't profitable or an efficient use of their time. Breeding tolerance and poltitical correctness has made it impossible to keep a high technical level discussion in RT without much more active trade participation and numerous voices.

Karl's position of moving Pricescope forward as a leader in diamond education and research is a great principal, and is the main reason why I still post here, I don't see that happening in RT threads not now not in the near future.

The prevailing preference here is to dumb everything down and to focus on "S" instead of the "O" that way most consumers will be able to understand at their education level without too much effort.

Thank goodness for the new DIamond Research forum where the "S" by itself really carries much less weight.

 

[risingsun]

Re: How important are HCA factor grades in assessing diamond

CCL~I think that there are a number of us on PS who do try to distinguish between the science and the subjective and understand the relationship between the two. I believe that many of us do not become involved in these types of threads anymore, if at all. I have made my reasons and frustrations clear, in my other posts, why I continue to be a part these threads. I will continue to participate until my frustrations outweigh my education. I think this is before you joined PS, but we had online webinars on a variety of topics. The educational piece of PS was robust. We were able to ask questions and receive information in real time. It was done in a very positive manner. I wish we could recapture that love of learning.

 

[Lula]

Re: How important are HCA factor grades in assessing diamond

CCL~I think that there are a number of us on PS who do try to distinguish between the science and the subjective and understand the relationship between the two. I believe that many of us do not become involved in these types of threads anymore, if at all. I have made my reasons and frustrations clear, in my other posts, why I continue to be a part these threads. I will continue to participate until my frustrations outweigh my education. I think this is before you joined PS, but we had online webinars on a variety of topics. The educational piece of PS was robust. We were able to ask questions and receive information in real time. It was done in a very positive manner. I wish we could recapture that love of learning.

Yes, risingsun, I agree. When I started lurking several years ago, and even when I became a member, a year and a half ago, there were far more education-for-education's sake threads. It's why I stopped being a lurker and became a member. I think if you look at the timeline when a certain poster joined PS, you'll notice a correlation -- not causation, but a correlation -- between the increase in posting on the part of a certain poster and an increase in the focus on "subjectivity" over "objectivity" that has overrun the educational threads to the point that they become combative.

Thank you, Karl, for saying what I've been thinking for a long time -- I didn't come here to learn about "good enough" stones. I came here to learn the difference between "good enough" and the best (which PS has taught me, largely through reading the archives on the old version of PS when the search function worked!). But now I find myself having to "defend" a broader range of purchase options than I would prefer, to avoid being labeled a shill, or to avoid having a new poster's thread derailed by those with a more traditional agenda.

I understand that PS is a business, and that most of the diamonds sold today are still sold by traditional "trust your eyes" jewelers at huge mark-ups. And I do wonder if the downturn in the economy has led PS to pursue a more middle-of-the-road diamond buying mentality rather than the maverick (cringing a little at using that word) nature of the PS of the past.

And, yes, I agree, CCL, the diamond research forum does have more of the feel of the old RT, but I have a hunch that won't last long, as the interests of the traditional diamond industry become threatened by the information in that forum. The dumbing down will no doubt occur there, too, as consumers find their way to that forum and representatives from the status quo seek to squelch their curiosity!

Just to clarify, I am not a fan of the paper buyers who buy only on what the paper says, but I also don't believe you can "trust your eyes" if your eyes have only the limited selection of your local jewelers' in front of you.

 

[Rockdiamond]

Re: How important are HCA factor grades in assessing diamond

Let's agree that it's possible to measure how much light comes out of the diamond, in a given environment.
However if we do that, the result is NOT "Light Performance"- unless we move back to the subjective judgement.
We would be measuring "Light Return".
IN this context, the word "performance" is in the realm of interpretation. We all agree that 100% light return is something like a mirror, and not desired.

Further, the measurement of light return ( as AGS might do) uses certain givens that may not hold true to real life, or how the diamond is viewed.
For sure diamonds react differently the different lighting scenarios.

Please dont start word games as its my weakness and you are going to make me work to hard.

The physical measuring of light return results in a few numbers that really doesnt mean much to me (and shouldnt to you either unless you wish to dive deep into the science), obviously the highest the better (I presume in a correct combination) but we all know we dont want a mirror on our finger .

I am looking more into the behaviour of the light return. Yes behaviour can be subjective but to be able to achieve the results a super precise cut can deliver you need to live in peace with the fact that light return can be objectively measured.

RD, I believe all Diamonds are potentially beautiful (even rough)...



So please stop preaching this tune as I and others already know and admitted beauty is subjective!

You keep voicing the "trade" at large (outside of PS) as reliable examples in your many discussions..., we are discussing issues 90%+ (I feel super safe with the + ) of the members of our trade/industry wouldnt even know is in existence. Its sad but true!

Well at least we know it did penetrate a bit as you yourself said you are starting to add Aset images to your products.

Yoram- I did not mean to play on words- "Correct Combination" is an area that is open to interpretation. Who gets to decide which is "the best" combination of scintillation, contrast, sparkle, brightness, spread, etc?
To make my point lets use cars as an analogy.
Compare the BMW M3 with the Mercedes C63.
Which performs better? That is a subjective call.
Which is faster 0-60? That is an objective measurement.
The Mercedes is faster 0-60, yet many will prefer the overall performance of the M3- based on subjective judgement.

What I see happening here that seems to be a difference in how we see brands-
For the best example of how certain brands are preferred by some, let's look at the GIA EX cut grade versus AGSL 0 cut grade.
Does a stone that gets both AGS 0 and GIA EX cut grade "perform better" than one getting only GIA EX?
For some, yes.
Can it be proved that such stones are objectively "better" than stones not earing AGS 0 yet achieving GIA's EX cut grade? I don't see how we can do that.

The stone I used as an example was by no means "good enough"- it was spectacular, and there's been zero "scientific" proof to dispute that.
GIA called it "Excellent Cut"- which to me, says something important. The stone suffered no ill effects of badly cut stones.
It was remarkably bright and looked every bit it's weight. I very much prefer this combination of sparkle contrast and scintillation to the more traditional "Ideal" cut. I also love "Ideal Cut" type stones- but I prefer the lack of pattern - especially in large stones.

I agree that 90%+ of the trade is both not knowledgeable in this subject. However how many of the remaining percentage even knows about this conversation?
PS is an awesome forum, with great readership, but some of the most respected names in the business don't participate.

Yoram- PS that's an ugly peice of rough
Since I like you so much, I'll take it off your hands for $100 per carat


Garry- I've delved into the article a bit- interesting stuff- and extremely pertinent to this discussion.
Thank you for posting it.

 

[diagem]

Re: How important are HCA factor grades in assessing diamond

The stone I used as an example was by no means "good enough"- it was spectacular, and there's been zero "scientific" proof to dispute that.

Was spectacular in your opinion (and perhaps could have been in mine as well if I had a chance to see it), but obviously was not "good enough" for some.
A simple cut quality test on DC would be able to reveal light return measurements. But its not available anymore so its a non issue as far as I am concerned.

PS is an awesome forum, with great readership, but some of the most respected names in the business don't participate.

But some definitely do. Most dont even know of its existence. For some reason, some professional industry media channels do not endorse a place of such level of transparency and open education. Signs of old school primitiveness??

Yoram- PS that's an ugly peice of rough
Since I like you so much, I'll take it off your hands for $100 per carat

Thats a beauty compared to the cut stone that came out of it

 

[Lula]

Re: How important are HCA factor grades in assessing diamond

The problem I see on PS, and specifically on RT, goes beyond brands, RD. It's the gradual eroding of the pursuit of knowledge re what is the best cut. It's the dodo bird philosophy -- "all have won and all must have prizes."

I'm sorry, but when it comes to RB's (old cuts, fancy cuts - different story) I just won't agree that a "random Gia ex" -- or however Karl put it -- is equivalent to a super-ideal. Ditto for GIA VG's. The margin of error for cut quality under those grades is just too broad for me.

And, RD, I also wish you'd quit crying wolf about "some of the most respected names in the trade don't participate here." Without names and a review of their credentials re respectability (most respected by whom?) that statement sounds more like a taunt designed to discredit the effort the many people (trade and prosumers) have put into developing and maintaining PS as a diamond education site that promotes and nurtures scientific advancement.

This thread is where things began to tank, imho
https://www.pricescope.com/community/threads/a-discussion-on-bias.120876/

I don't think PS ever fully recovered from that thread.
eta: take a look at that thread and note how many longtime prosumers, with post counts in the thousands, no longer post on RT and/or on PS -- I don't think that's due to normal forum attrition, but rather the lack of respect on the part of vendors toward many prosumers during that time and the months that followed.

And I sincerely think that it was that thread that began the drift toward PC-ness on PS, and the descent into the "every diamond is worthy" view that now permeates RT.

At the time that thread was posted, RD had approximately 400 posts to his name -- I know this, because in that thread I commented on the vendors' relative post counts. A little over a year later, RD has over 2000 posts; many of them with the same "theme," if you will.

I often thought the posters who claimed that RD's participation on RD and his devil's advocate positions were just a ruse to draw people to his site and improve his stats on search engines were taking things a little too far -- now I'm not so sure.

All I know is that, as a prosumer who was really excited about learning the details about diamond cut and advances in the field, and who felt good about helping others "see the light" (pun intended) about the importance of cut quality, I no longer feel good about volunteering my time here if it means I have to walk on egg shells to avoid offending vendors who seek to muddy the waters about the importance of cut quality, objective measurement, and scientific advancement, to confuse consumers and push consumers back into the world of "good enough" cut.

There are many, many more vendors selling "good enough" cut diamonds than there are vendors selling super-ideal diamonds. Those "good enough" vendors benefit from RD's gadfly approach, and they benefit every time there is a debate about the objectivity of reflector technology.

 

[ChunkyCushionLover]

Re: How important are HCA factor grades in assessing diamond

The problem I see on PS, and specifically on RT, goes beyond brands, RD. It's the gradual eroding of the pursuit of knowledge re what is the best cut. It's the dodo bird philosophy -- "all have won and all must have prizes."

I'm sorry, but when it comes to RB's (old cuts, fancy cuts - different story) I just won't agree that a "random Gia ex" -- or however Karl put it -- is equivalent to a super-ideal. Ditto for GIA VG's. The margin of error for cut quality under those grades is just too broad for me.

And, RD, I also wish you'd quit crying wolf about "some of the most respected names in the trade don't participate here." Without names and a review of their credentials re respectability (most respected by whom?) that statement sounds more like a taunt designed to discredit the effort the many people (trade and prosumers) have put into developing and maintaining PS as a diamond education site that promotes and nurtures scientific advancement.

This thread is where things began to tank, imho
https://www.pricescope.com/community/threads/a-discussion-on-bias.120876/

I don't think PS ever fully recovered from that thread.
eta: take a look at that thread and note how many longtime prosumers, with post counts in the thousands, no longer post on RT and/or on PS -- I don't think that's due to normal forum attrition, but rather the lack of respect on the part of vendors toward many prosumers during that time and the months that followed.

And I sincerely think that it was that thread that began the drift toward PC-ness on PS, and the descent into the "every diamond is worthy" view that now permeates RT.

At the time that thread was posted, RD had approximately 400 posts to his name -- I know this, because in that thread I commented on the vendors' relative post counts. A little over a year later, RD has over 2000 posts; many of them with the same "theme," if you will.

I often thought the posters who claimed that RD's participation on RD and his devil's advocate positions were just a ruse to draw people to his site and improve his stats on search engines were taking things a little too far -- now I'm not so sure.

All I know is that, as a prosumer who was really excited about learning the details about diamond cut and advances in the field, and who felt good about helping others "see the light" (pun intended) about the importance of cut quality, I no longer feel good about volunteering my time here if it means I have to walk on egg shells to avoid offending vendors who seek to muddy the waters about the importance of cut quality, objective measurement, and scientific advancement, to confuse consumers and push consumers back into the world of "good enough" cut.

There are many, many more vendors selling "good enough" cut diamonds than there are vendors selling super-ideal diamonds. Those "good enough" vendors benefit from RD's gadfly approach, and they benefit every time there is a debate about the objectivity of reflector technology.

Excellent summary and insight Portree. I haven't been here long enough to know all the history but at this point its hard to argue with Leonid's (old admins) decision to ban Excel(Barry and Judah) and Rockdiamond from posting here for a long period. The shill sites for Excel still exist, that bias thread really presented Judah just like his father continuing the same behaviour. Rockdiamond, well same old, as long as he posts as he does we will have the same type of threads over and over again until every experienced prosumer and most trade are fed up and stop replying, and then he can just mislead novices however he pleases.

A whole lot of noise from a vendor who barely sells any colorless diamonds. Pretty sick
Customers don't need pricescope to choose any random GIA Excellent or a GIA very good round, they can walk into a B&M, overpay, and be none the wiser.

Consumers who come here have already been exposed to "Good enough" now they are coming here for "Better". I just don't get the persistant need to point out the obvious and protect the trade at large who isn't as familiar with these things.

HCA happened to downgrade a stone such as this one, it was a correct call it doesn't deserve to be below 2 on HCA. Whether it deserves a 2.5 or 5.5 really makes very little difference to the general advice given here. Using that example to throw out HCA as providing false negatives and not being useful enough really is a very luddite and anti educational position.

 

[Karl_K]

Re: How important are HCA factor grades in assessing diamond

The problem I see on PS, and specifically on RT, goes beyond brands, RD. It's the gradual eroding of the pursuit of knowledge re what is the best cut. It's the dodo bird philosophy -- "all have won and all must have prizes."

I'm sorry, but when it comes to RB's (old cuts, fancy cuts - different story) I just won't agree that a "random Gia ex" -- or however Karl put it -- is equivalent to a super-ideal. Ditto for GIA VG's. The margin of error for cut quality under those grades is just too broad for me.

And, RD, I also wish you'd quit crying wolf about "some of the most respected names in the trade don't participate here." Without names and a review of their credentials re respectability (most respected by whom?) that statement sounds more like a taunt designed to discredit the effort the many people (trade and prosumers) have put into developing and maintaining PS as a diamond education site that promotes and nurtures scientific advancement.

This thread is where things began to tank, imho
https://www.pricescope.com/community/threads/a-discussion-on-bias.120876/

I don't think PS ever fully recovered from that thread.
eta: take a look at that thread and note how many longtime prosumers, with post counts in the thousands, no longer post on RT and/or on PS -- I don't think that's due to normal forum attrition, but rather the lack of respect on the part of vendors toward many prosumers during that time and the months that followed.

And I sincerely think that it was that thread that began the drift toward PC-ness on PS, and the descent into the "every diamond is worthy" view that now permeates RT.

At the time that thread was posted, RD had approximately 400 posts to his name -- I know this, because in that thread I commented on the vendors' relative post counts. A little over a year later, RD has over 2000 posts; many of them with the same "theme," if you will.

I often thought the posters who claimed that RD's participation on RD and his devil's advocate positions were just a ruse to draw people to his site and improve his stats on search engines were taking things a little too far -- now I'm not so sure.

All I know is that, as a prosumer who was really excited about learning the details about diamond cut and advances in the field, and who felt good about helping others "see the light" (pun intended) about the importance of cut quality, I no longer feel good about volunteering my time here if it means I have to walk on egg shells to avoid offending vendors who seek to muddy the waters about the importance of cut quality, objective measurement, and scientific advancement, to confuse consumers and push consumers back into the world of "good enough" cut.

There are many, many more vendors selling "good enough" cut diamonds than there are vendors selling super-ideal diamonds. Those "good enough" vendors benefit from RD's gadfly approach, and they benefit every time there is a debate about the objectivity of reflector technology.

well said
I will say that as long as one person wants to learn I will do my best to teach even if I have to drown out a dozen cape crusaders of the decades past to do so.

 

[Regular Guy]

Re: How important are HCA factor grades in assessing diamond

This thread is where things began to tank, imho
https://www.pricescope.com/community/threads/a-discussion-on-bias.120876/

I don't think PS ever fully recovered from that thread.
eta: take a look at that thread and note how many longtime prosumers, with post counts in the thousands, no longer post on RT and/or on PS -- I don't think that's due to normal forum attrition, but rather the lack of respect on the part of vendors toward many prosumers during that time and the months that followed.

And I sincerely think that it was that thread that began the drift toward PC-ness on PS, and the descent into the "every diamond is worthy" view that now permeates RT.
.

well said
I will say that as long as one person wants to learn I will do my best to teach even if I have to drown out a dozen cape crusaders of the decades past to do so.

Very interesting walk down memory lane.

I will say, again, I agree with much of this (though I'm surprised with the current search engine you could find that older thread, much less think to identify it)...and in fact, I see that I pointed to the substance of that very thread in the contemporary thread on Trade Participation on PS, on page 7 of that thread, also here:

https://www.pricescope.com/forum/announces/trade-participation-on-pricescope-t149926-180.html

So..I've really nothing new to add, except to also see from Neil's comments on page 11 of that older thread that nothing substantive has changed in now quite a long time, and a great deal of stagnation has seemingly allowed to occur overall on his boad. To what benefit, it is not clear...although Serg had offered something in the way of a theory....he has not been around of late to either seek to add additional support to his ideas, nor anything much else.

Garry has shared about the scientific apocryphal story of the frog who will jump out of the water, when thrown into boiling water, but instead, will just stick around and die if put into water that slowly goes to a boil instead. It may be helpful to consider the possible application of this story to Pricescope. If that is how this board, and decisions around it work....what messaging can we get to the frog?

Ira Z.

 

[risingsun]

Re: How important are HCA factor grades in assessing diamond

Sara~I agree with every word of your post. You had the courage to say the things that I didn't say in my own post. I took a look at the thread for which you provided a link. I didn't reread it, but I remember it well. It almost led to my leaving PS. I felt coerced into apologizing to someone who exhibited a rude and condescending attitude toward me and others. I agree that after that thread and many like it, I didn't feel safe in recommending diamonds. For quite some time, I didn't feel safe on this site at all. Like you, I am no longer willing to keep silent about it. The loss to PS, of long-term posters, has been shocking. These people were a valuable resource that PS could not afford to lose. Count the number of people who are still here and struggling to regain a resource that provides current education and look at who is no longer at a part of it. I absolutely believe that the thread you referenced did significant damage to this forum. Subsequent trips down that same road have added to it. Ira, I must say that I'm feeling somewhat like a boiled frog these days....

 

[goodgal]

Re: How important are HCA factor grades in assessing diamond

RD,

Here is an overlap of the AGSPGS with GIA grading for 60% table diamonds.
Letter grades are GIA proportion grading, number grades are from AGS Performance Grading Software (80% LGF and stars 55%, Girdle Bezel 3%)



From http://www.octonus.com/oct/mss/gia&agspgs.phtml

26 GIA Ex - AGS0
2 GIA EX - AGS 1 (Shallow Crown)
4 GIA EX - AGS 2 (Very Steep Pavilion with Tall Crown) or (Steep Pavilion with Very Tall Crown)
5 GIA EX - AGS 3 (Very Steep pavilion combined with Very Tall Crown)

The overlap and agreement between the GIA EX and AGS 0 is pretty good for most of the highest grades. The exception is AGS penalizes some combinations due to loss of brightness and leakage under the table. Overall AGSL has more precise tiers which differentiate more at the highest level of performance.

More consumer confusion...
If I read this correctly a crown angle of 31.5 with a 41.6 pav angle =Gia excellent or AGS0??? HCA score I get is 3.8

 

[2023]

Re: How important are HCA factor grades in assessing diamond

This was really interesting to read, sorry I can't do the correct quoting.

About the HCA from Gary Hollaway
"GIA's system is pretty much a direct copy (IMHO they should never have been granted a patent over mine which predates theirs) and works in much the same way by accessing a database of different factors such as my 4 and gives a final grade (except they do not give you the word answers). I have a desk top that gives my numeric data too.

However any system like this is only as good as the charts they look up. If I had been smart enough to commercialize mine I would do better charts knowing what I know and with the tools I have. But this is not easy work, and if or when I do it, I will do it well."

And the last poster also had a really interesting point, unfortunately no reply!

Thanks for the open debate for learners to read PS!