Trying to understand the HCA just a little better....

[aljdewey]

Date: 11/9/2005 4:40:21 PM
Author: Regular Guy
Al,

Do you understand this post started in May, with a couple of posts today (that did not originate with me, although I did remind Garry of it)? I did make one post today. Is there anything in my post today you''re responding to?

No, I didn''t realize that.....I don''t think I looked at the date until Garry''s chart, which was dated today.

In all honestly, the post is as timely today as it was then.....particular given yesterday''s conversations about the HCA and how to interpret (or not) the various scores.

This really fits hand in hand with questions you continued to ask as recently as yesterday regarding relative scoring in the HCA.

 

[Garry H (Cut Nut)]

Date: 11/9/2005 5:05:45 PM
Author: aljdewey

Date: 11/9/2005 4:40:21 PM
Author: Regular Guy
Al,

Do you understand this post started in May, with a couple of posts today (that did not originate with me, although I did remind Garry of it)? I did make one post today. Is there anything in my post today you''re responding to?

No, I didn''t realize that.....I don''t think I looked at the date until Garry''s chart, which was dated today.

In all honestly, the post is as timely today as it was then.....particular given yesterday''s conversations about the HCA and how to interpret (or not) the various scores.

This really fits hand in hand with questions you continued to ask as recently as yesterday regarding relative scoring in the HCA.

Exactly Alj, and this is why i migrated the discussion to this old Ira thread.

So we all agree HCA is for pre-sorting, not final selection.

Now look at the crude markings I have put on the chart. Does this help anyone?

Does everyone understand the charts - there are several in 1% table size - and the pavilion angle is verticale - crown along the bottom.

The idea is that diamonds along the slope of about 30 degrees actually look and perform the same as each other over a few degrees of crown angle range. They look and behave THE SAME.
So using ideas like pavilion angle should be not less than 40.5 are dead dumb ideas.

The world behaves to certain rules. We call these the rules or laws of physcis.

 

[strmrdr]

It would appear AGS disagrees with you Garry...

 

[Garry H (Cut Nut)]

Not true Storm.
Peter agrees about shallow stones for earrings and pendants.
And the young people range is spot on to their range.

AGS stated policy is that there should be no person that would not like any diamond they give AGS 0.
Even a person with a huge AFRO hair style and great close up vision.

BTW Strom - you are bouncing my emails

 

[Rhino]

Greetings mate,

Thanks for migrating things here. What you are all saying is fine and good but one point I would like to address which is not (and which was the topic of discussion in the other thread) was the issue of regulars here pointing to the HCA and saying "just get a stone that scores under 2 and you got an ideal". I realize folks here have been weened on HCA scores and IS images and believe me, I know quite intimately the value of this information but Garry ... we''ve got to dispell the notion that people can come here, plug numbers into the HCA and be led to believe they are getting an ideal cut diamond just because the stone scores less than a 2.

I would make this qualifying statement based on the studies I''ve conducted thus far and I am interested to hear your input of course.

A stone scoring under a 2 on the HCA is no guarantee that the diamond is "AGS Ideal" or "GIA Excellent" in light performance (according to the most recent advances in cut grading). There are lighting environments in which all stones under a 2 will look just fine in but there are other environments in which it will not look as good, hence non ideal.

I believe it is a good "pre-sorting" tool if indeed you know what it is you are sorting for. This involves learning client preferences and needs. I would not agree that it is a good presorting tool for ideal cut diamonds because it is impossible to guarantee that based on the way the HCA software is constructed.

Currently the only ways to identify AGS or GIA ideals in the new system of things are ...

AGS:
1. Of course a lab report.
2. AGS has released charts which one can reference in the "cutting guidelines".
3. Lastly AGS Jewelers have access to their "Performance Grading Software" in which they can upload models generated via the non-contact scanners (Helium, Sarin, OGI)

GIA:
1. Since new lab reports are not coming until January there is currently FacetWare however there is one metric not covered in Facetware and those would be the effects girdle cutting (painted, digging and classical). So technically if a stone checks fine on Facetware but the upper halves have been painted or dug out the stone would not get ideal rating. To what degree the painting and digging it is is unknown to me at this time.
2. Sarin has released a plug in (a rather expensive one at that) which automatically assigns the GIA grade based on the scan. There is an additional "recut'' plug in which shows the results of a recut stone guaranteeing GIA Excellent. What''s neat about this is it will also show you the differences in Octonus with that plug in. Very cool.

If I''m leaving anything out please let me know.

What I particularly like about both systems is the wide variety of appearances each system covers. It appears the GIA system may be slightly more liberal regarding minor facet cutting but they both appear to both be pretty close in many regards. As I''ve noted in another thread GIA appears to be more on the conservative side regarding the shallow/shallow combos and more liberal on the steep/deeps while AGS a little more liberal on the shallow/shallows and more conservative on the steep/deeps.

I''m interested in your thoughts mate.

Peace,

 

[Garry H (Cut Nut)]

Date: 11/9/2005 11:42:55 PM
Author: Rhino
Greetings mate,

I realize folks here have been weened on HCA scores and IS images and believe me, I know quite intimately the value of this information but Garry ... we''ve got to dispell the notion that people can come here, plug numbers into the HCA and be led to believe they are getting an ideal cut diamond just because the stone scores less than a 2.

I would make this qualifying statement based on the studies I''ve conducted thus far and I am interested to hear your input of course.
I get tired of saying the same thing - HCA is for rejection, not selection.

GIA:
1. Since new lab reports are not coming until January there is currently FacetWare however there is one metric not covered in Facetware and those would be the effects girdle cutting (painted, digging and classical). So technically if a stone checks fine on Facetware but the upper halves have been painted or dug out the stone would not get ideal rating. To what degree the painting and digging it is is unknown to me at this time. I am sure you ahve all noticed a much larger proportion of stones with painting or digging - so this will be very interesting, and I do not believe the Sarin system accounts for it - as the complexity of proportions is far greater than GIA could have established with 70k observations. I think we are going to witness big huma grading variances because of upper and lower gridle facet treatments from GIA
2. Sarin has released a plug in (a rather expensive one at that) which automatically assigns the GIA grade based on the scan. There is an additional ''recut'' plug in which shows the results of a recut stone guaranteeing GIA Excellent. What''s neat about this is it will also show you the differences in Octonus with that plug in. Very cool. As I have said - Sarin will not guarantee a GIA grade.

But Jon this discussion is not that relevant to the chart above.
You have presumably been searching for well cut BIC''s and FIC''s?

That stone that Brad and Jan posted a year or 2 back (to show that HCA does not work) - that was an excellent example of the type of stone, that if well cut with TLC - then there can be a big range of very attractive stones. Can anyone find a link to it?

 

[strmrdr]

Date: 11/9/2005 8:32:34 PM
Author: Garry H (Cut Nut)
Not true Storm.

Peter agrees about shallow stones for earrings and pendants.

And the young people range is spot on to their range.


AGS stated policy is that there should be no person that would not like any diamond they give AGS 0.

Even a person with a huge AFRO hair style and great close up vision.


BTW Strom - you are bouncing my emails

I agree they are mostly passing those that are good for all uses and all people.
The kewl thing is that people that arent going to use them for rings can save some bucks when buying earring and pendant diamonds.

Which is exackly the point Iv been making all along and getting attacked for.

edit> your isp got put on a spam list and blocked by my isp I sent you my other email addy.
You might want to contact your isp's support department with the content of the bounce message.

 

[glitterata]

Looky look, Storm, you posted at 1:11:11 on 11/10! Just do it again tomorrow and you''ll have a REALLY neato number.

 

[strmrdr]

Date: 11/10/2005 1:40:27 AM
Author: glitterata
Looky look, Storm, you posted at 1:11:11 on 11/10! Just do it again tomorrow and you''ll have a REALLY neato number.

lol hopefully ill be sleeping this time tomorrow night.....

 

[belle]

Date: 11/9/2005 11:42:55 PM
Author: Rhino
Greetings mate,

Thanks for migrating things here. What you are all saying is fine and good but one point I would like to address which is not (and which was the topic of discussion in the other thread) was the issue of regulars here pointing to the HCA and saying 'just get a stone that scores under 2 and you got an ideal'. I realize folks here have been weened on HCA scores and IS images and believe me, I know quite intimately the value of this information but Garry ... we've got to dispell the notion that people can come here, plug numbers into the HCA and be led to believe they are getting an ideal cut diamond just because the stone scores less than a 2.

I would make this qualifying statement based on the studies I've conducted thus far and I am interested to hear your input of course.

A stone scoring under a 2 on the HCA is no guarantee that the diamond is 'AGS Ideal' or 'GIA Excellent' in light performance (according to the most recent advances in cut grading). There are lighting environments in which all stones under a 2 will look just fine in but there are other environments in which it will not look as good, hence non ideal.

i will say it again, hca is a tool for rejection not selection.
using hca, we all know that scores under 2.0 means that you have eliminated known poor performers (95% of the diamonds) and it only stands to reason that those left in the top 5% are amongst the best. i am curious, what would you call those that reach the top 5%?

actually, forget scores under 2.0 and the top 5% for now and answer me this.. what would be the term you would use for the group of stones (as a whole) that are currently graded as either ags ideal or gia excellent?
would you call those ideal?

what about all of the stones that were graded as ideal under the old ags system that is still being used today? are those ideal?

what about that stone that not yet graded stone that looks like, according to facetware, will grade as 'excellent' come january?
is it ideal?

what if that disclaimer on facetware was right and the stone only graded as 'very good' is it now out as ideal?

no one has said or even suggested that stones scoring under 2.0 would be (according to the most recent advances in cut grading) ags ideal or gia excellent or even implied it. that would be especially difficult since both systems have been/are currently changing their cut grading system. so please don't suggest that only stones with the right document at the right time are the only ones that can be considered ideal because the bottom line is, the term 'ideal' is widely applied and accepted in this industry, but it seems to at least have the most appropriate place here.

Date: 11/9/2005 11:42:55 PM
Author: Rhino

I believe it is a good 'pre-sorting' tool if indeed you know what it is you are sorting for. This involves learning client preferences and needs.

tell me you didn't really mean this.
you are implying that the average person cannot properly use the hca for himself and that only those who 'learn client
preferences and needs' (indicating a vendor) are qualified to interpret it.

 

[Garry H (Cut Nut)]

Belle you are one of the 5% ideal women who can ACTUALLY THINK for yourself. (only 1% of men can think for themselves - see I am not beiong sexist (hang on - that 1% are not ''attached'' to a female - the other 4% of free thinking males do as they are told) )

So does that make you ''ideal'' or ''excellent'' (or a nagging wife / partner?)

Actually, AGS own "ideal" in USA.
GIA own "Excellent"
Since Ideal trumps excellent, AGS has the ''boutique'' position.

But Sergey and Yuri take offense at the word "ideal" because it suggests best that can not be bettered, and that is wrong. Just as Rhino has moved from 1st best (FS), to better still (LS), to bestest (BS) and on to even betterestest-ever-idealist (ISEE2) - we runs out of superdooper-superlatives.

What did Mary POppins say?

 

[Paul-Antwerp]

Date: 11/10/2005 5:18:35 AM
Author: Garry H (Cut Nut)
But Sergey and Yuri take offense at the word ''ideal'' because it suggests best that can not be bettered, and that is wrong. Just as Rhino has moved from 1st best (FS), to better still (LS), to bestest (BS) and on to even betterestest-ever-idealist (ISEE2) - we runs out of superdooper-superlatives.

When running out of superlatives, I would start calling it ''Infinite-Ideals''.

Just joking,

 

[strmrdr]

call em whatever you want..........

The heart of the matter is are some combos while good diamonds better suited for earring and pendant use.
The answer is YES.
What im trying to do is nail down where that point is and explain it in a simple manner.

 

[strmrdr]

te:[/b] 11/10/2005 3:29:47 AM
Author: belle
Author: Rhino


I believe it is a good 'pre-sorting' tool if indeed you know what it is you are sorting for. This involves learning client preferences and needs.
....................................................



tell me you didn't really mean this.

you are implying that the average person cannot properly use the hca for himself and that only those who 'learn client

preferences and needs' (indicating a vendor) are qualified to interpret it.

[/quote]

As a vendor he would not be doing his job if he blindly followed the hca under 2 is perfect saying.
In the under hca 2 range are a wide variety of diamond personalities and looks and quality.
He carries a wide range of diamonds with different personalities from the regent to the GOG classic h&a's when helping a client select one of them he needs to know what they prefer and what they are looking for to match them up with the best diamond for them.
Any one diamond with an hca score under 2 may not be the right match to a particular client and another might be.

Garry said it best a while back when he said along the lines of:
A good jeweler sells beautiful things and its his job to match up people with the right beautiful thing they will treasure for a lifetime.

What Rhino is saying in that the hca isn't precise enough to do that by itself.
Garry says the same thing.
I say the same thing.

He is not saying consumers cant use the hca many have, he is saying he can not blindly follow the hca as the deciding factor and neither should anyone else.

Lets face it when buying from the top PS vendors who provide a lot of information about their diamonds the hca is usualy used to make the person buying comfortable with what the vendor has selected not as a selection or rejection tool. :}

 

[belle]

Date: 11/10/2005 5:18:35 AM
Author: Garry H (Cut Nut)
Belle you are one of the 5% ideal women who can ACTUALLY THINK for yourself. (only 1% of men can think for themselves - see I am not beiong sexist (hang on - that 1% are not ''attached'' to a female - the other 4% of free thinking males do as they are told) )

So does that make you ''ideal'' or ''excellent'' (or a nagging wife / partner?)

Actually, AGS own ''ideal'' in USA.
GIA own ''Excellent''
Since Ideal trumps excellent, AGS has the ''boutique'' position.

But Sergey and Yuri take offense at the word ''ideal'' because it suggests best that can not be bettered, and that is wrong. Just as Rhino has moved from 1st best (FS), to better still (LS), to bestest (BS) and on to even betterestest-ever-idealist (ISEE2) - we runs out of superdooper-superlatives.

What did Mary POppins say?

i agree, which is why 95% (i''m being conservative here) of the time you will see me say ''well cut''.
it''s the same reason that for the most part i refer to a certain NSAID (non-steroidal anti-infllammatory) by it''s generic name of ibuprofin. if i called it only by it''s most popular name advil all the time, there are people who would think that was the only brand of ibuprofin. yet, there are times when i can say ''go take some advil'' and that person knows i am not saying, go and take only the most widely recognized form of ibuprofin, take any of them. i trust, given the situation, that this person knows there are many choices for ibuprofin, not just advil. i don''t have to walk them through it everytime.
so, have i used the term ideal? yep, i sure have. not everything has to be strained and spoonfed. people here are smart and should get more credit for being able to figure things out for themselves.

 

[Regular Guy]

Question: What does it mean when you say: Three''s a charm.

Answer: It''s what the third guy from Las Vegas means, when you have three guys in a row:

a bus driver
a lender at a bank
and a professional card player

asked what they do,

the first guy says: I drive a bus
the second guy says: I''m a banker
the third guy says: I deal

 

[belle]

Date: 11/10/2005 7:33:54 AM
Author: strmrdr
call em whatever you want..........

The heart of the matter is are some combos while good diamonds better suited for earring and pendant use.
The answer is YES.
What im trying to do is nail down where that point is and explain it in a simple manner.

that is your opinion. perhaps the reason you are feeling ''attacked'' is because when you say it, you state it as fact like you did here.
it is a preference just like any other characteristic of a diamond.

for example, i think i/j color diamonds are perfect for pendants/earrings and really wouldn''t consider anything of higher color. does that mean i want i/j for a ring? no. my preference is for less color in a ring.
do i, every chance i get, say that ''j'' color stones are better suited for pendants than rings? no. it is a personal preference. there are many people here that love their ''j'' color rings just as there are many people whole love their 40.6pa rings. for anyone to make definitive statements based solely on their personal preferences is ridiculous.

 

[strmrdr]

Date: 11/10/2005 10:41:23 AM
Author: belle

Date: 11/10/2005 7:33:54 AM

Author: strmrdr

call em whatever you want..........


The heart of the matter is are some combos while good diamonds better suited for earring and pendant use.

The answer is YES.

What im trying to do is nail down where that point is and explain it in a simple manner.

that is your opinion. perhaps the reason you are feeling 'attacked' is because when you say it, you state it as fact like you did here.

it is a preference just like any other characteristic of a diamond.


for example, i think i/j color diamonds are perfect for pendants/earrings and really wouldn't consider anything of higher color. does that mean i want i/j for a ring? no. my preference is for less color in a ring.

do i, every chance i get, say that 'j' color stones are better suited for pendants than rings? no. it is a personal preference. there are many people here that love their 'j' color rings just as there are many people whole love their 40.6pa rings. for anyone to make definitive statements based solely on their personal preferences is ridiculous.

pot kettle black :}
"any diamond under hca 2.0 is awesome" the world according to belle

Went out and actualy looked at one of these combos yet?

btw 4.6 isnt always a problem... more later....

 

[belle]

Date: 11/10/2005 11:02:52 AM
Author: strmrdr

Date: 11/10/2005 10:41:23 AM
Author: belle

Date: 11/10/2005 7:33:54 AM

Author: strmrdr

call em whatever you want..........


The heart of the matter is are some combos while good diamonds better suited for earring and pendant use.

The answer is YES.

What im trying to do is nail down where that point is and explain it in a simple manner.

that is your opinion. perhaps the reason you are feeling ''attacked'' is because when you say it, you state it as fact like you did here.

it is a preference just like any other characteristic of a diamond.


for example, i think i/j color diamonds are perfect for pendants/earrings and really wouldn''t consider anything of higher color. does that mean i want i/j for a ring? no. my preference is for less color in a ring.

do i, every chance i get, say that ''j'' color stones are better suited for pendants than rings? no. it is a personal preference. there are many people here that love their ''j'' color rings just as there are many people whole love their 40.6pa rings. for anyone to make definitive statements based solely on their personal preferences is ridiculous.

pot kettle black :}
Went out and actualy looked at one these combos yet?

 

[belle]

Date: 11/10/2005 11:02:52 AM
Author: strmrdr

Date: 11/10/2005 10:41:23 AM
Author: belle

Date: 11/10/2005 7:33:54 AM

Author: strmrdr

call em whatever you want..........


The heart of the matter is are some combos while good diamonds better suited for earring and pendant use.

The answer is YES.

What im trying to do is nail down where that point is and explain it in a simple manner.

that is your opinion. perhaps the reason you are feeling 'attacked' is because when you say it, you state it as fact like you did here.

it is a preference just like any other characteristic of a diamond.


for example, i think i/j color diamonds are perfect for pendants/earrings and really wouldn't consider anything of higher color. does that mean i want i/j for a ring? no. my preference is for less color in a ring.

do i, every chance i get, say that 'j' color stones are better suited for pendants than rings? no. it is a personal preference. there are many people here that love their 'j' color rings just as there are many people whole love their 40.6pa rings. for anyone to make definitive statements based solely on their personal preferences is ridiculous.

pot kettle black :}
'any diamond under hca 2.0 is awesome' the world according to belle

Went out and actualy looked at one of these combos yet?

btw 4.6 isnt always a problem... more later....

oh i see, you edited your post for 'clarification'.
would you like to edit that again, or are you going to leave it and suggest it to be true?

 

[strmrdr]

naw im done editing :}
i figured you would be able to figure it out what I was talking bout but someone else might not.

 

[belle]

actually the

still stands.
please explain your post.

 

[aljdewey]

Date: 11/10/2005 8:05:42 AM
Author: strmrdr

As a vendor he would not be doing his job if he blindly followed the hca under 2 is perfect saying.

Storm, who asked him to? You are arguing a point that''s moot because no one has said "hca under 2 is perfect". Just didn''t happen. The people he''s arguing with have said "HCA under 2 is a good starting point". That''s all.

Date: 11/10/2005 8:05:42 AM
Author: strmrdr

when helping a client select one of them he needs to know what they prefer and what they are looking for to match them up with the best diamond for them.
Any one diamond with an hca score under 2 may not be the right match to a particular client and another might be.

Any vendor "needs to know" what a customer prefers...and all he has to do is ask. But "match the best diamond with that customer?" C''mon - it''s not a DATING service, it''s a diamond!

What I bristle at is the iimplication that a customer cannot identify or decide for himself what his own preferences are without help. That is just ludricrous. I don''t need someone to tell me what I should prefer or what I do prefer. I am (and most people I know are) quite capable of identifying what I like without having someone hold my hand and influence my preferences.

The idea that someone else can do a BETTER job of selecing what *I* will like than I can myself.....preposterous.

Date: 11/10/2005 8:05:42 AM
Author: strmrdr

Any one diamond with an hca score under 2 may not be the right match to a particular client and another might be.

It bears repeating until everyone gets it.....there has been no suggestion that EVERY diamond scoring under 2 on the HCA---or even any individual diamond within that group----will please a given customer. This is an incorrect interpretation of the comments made.

Date: 11/10/2005 8:05:42 AM
Author: strmrdr

What Rhino is saying in that the hca isn''t precise enough to do that by itself.
Garry says the same thing.
I say the same thing.

You aren''t and haven''t been the *only* ones saying that.

In fact, the only contributor that I can think of who wants to find a way for HCA results to be used as a stand-alone tool is Ira. It''s own creator, Garry, has said several times that''s not intended to be relied on solely. I''ve said it. You''ve said it. Again, you''re arguing a moot point that no one disagrees with.

Date: 11/10/2005 8:05:42 AM
Author: strmrdr

He is not saying consumers cant use the hca many have, he is saying he can not blindly follow the hca as the deciding factor and neither should anyone else

And AGAIN, he''s not the only one saying that......and he never has been.

Date: 11/10/2005 8:05:42 AM
Author: strmrdr

Lets face it.......the hca is usualy used to make the person buying comfortable with what the vendor has selected , not as a selection or rejection tool. :}

That''s not something that can be mandated, Storm. You can tell people over and over (and believe me, I HAVE) that the HCA isn''t supposed to be used that way....but you can''t force people to heed the advisory. That''s true of almost anything. People are told daily the perils of drinking/driving, and yet it persists.

The reality is that some people will disregard sound advice, and there''s nothing you can do about it. The fact that some people will misuse a useful tool doesn''t negate it''s potential value for those who decide to use it properly and for its intended use.

That''s where the disagreement comes in. The argument keeps being asserted that it''s not useful as a preselection tool for "ideal" diamonds. Ideal according to who? Ideal is a generic term; it''s NOT standardized.
The ONLY savvy anyone needs to properly use the HCA is decent reading comprehension skills. THIS is what HCA says it does: it eliminates 95% of poor performers. THAT''S IT....THAT''S ALL. People who use it need to have the comprehension to understand what it means. In that context, I assert that it ABSOLUTELY is a useful sorting tool.

 

[aljdewey]

Date: 11/10/2005 1:11:11 AM
Author: strmrdr

The kewl thing is that people that arent going to use them for rings can save some bucks when buying earring and pendant diamonds.

Which is exackly the point Iv been making all along and getting attacked for.

Storm, with every due respect to you.......disagreement with your point of view does not rise to the level of "getting attacked". It''s just disagreement.....intellectual disagreement. It seems like a pretty basic elemental concept to me that not everyone will agree with everything you say, everything I say, or everything ANYONE says. Why do you have to interpret disagreement with your viewpoint as a personal attack?

Opinions cannot be wrong, Storm....it''s what you believe. But you have to accept that other people aren''t going to believe in what you do...part of life.

To your point about shallow stones for a second. I''m not disagreeing with that opinion at all......but I believe that one opinion does not fit all. Some folks would agree with your preference to use such stones as earrings/pendants; others wouldn''t care for it.

I am curious, though, about your assertion that selection of said stones can "save a few bucks". Stones that you''ve pointed to previously as "better for pendant" stones.....off the top of my head, I cannot say that I saw any difference or savings in the price-per-carat of these stones. Where are you looking that suggests such stones offer any savings---significant or otherwise?

 

[Garry H (Cut Nut)]

Date: 11/10/2005 11:42:51 AM
Author: aljdewey

Date: 11/10/2005 1:11:11 AM
Author: strmrdr

The kewl thing is that people that arent going to use them for rings can save some bucks when buying earring and pendant diamonds.

Which is exackly the point Iv been making all along and getting attacked for.

To your point about shallow stones for a second. I''m not disagreeing with that opinion at all......but I believe that one opinion does not fit all. Some folks would agree with your preference to use such stones as earrings/pendants; others wouldn''t care for it.

I am curious, though, about your assertion that selection of said stones can ''save a few bucks''. Stones that you''ve pointed to previously as ''better for pendant'' stones.....off the top of my head, I cannot say that I saw any difference or savings in the price-per-carat of these stones. Where are you looking that suggests such stones offer any savings---significant or otherwise?

OK, you''ve all been round in a circular arguement.
How''s about while i go for my run, some of you dom searches by shallow depth % and by ''nornal'' depth % - and see if there is a difference in price?

Lets look for opportunities and move on.....

 

[valeria101]

Date: 11/10/2005 1:52:29 PM
Author: Garry H (Cut Nut)

How''s about while i go for my run, some of you dom searches by shallow depth % and by ''nornal'' depth % - and see if there is a difference in price?

GIA, 1.01-1.05 cts G-VS2, table 53-58


If depth between 57-59, prices run from 6k to 7k

If depth between 60-63, prices run from 5k to 8k


But... some in the first batch seem a hair larger than the average bit in the other group (6.6 versus 6.5) or so.

Big deal?


Better run too!

 

[Rhino]

Ok... sticking to the informational content of this thread. Alj, please do not take my questions/comments on the information personally. They are not directed at *you* but at the information presented.

Date: 11/9/2005 4:32:18 PM
Author: aljdewey

My point: the thing doesn''t have to meet NASA accuracy calibrations to provide a ''starting'' point for weeding out stones. That type of MICRO difference is more meaningful in the 2nd and 3rd round of elimination, but NOT the first....which is what the HCA amounts to: a first-round elimination.

This raises the question: First round of elimination for what? Ideal cuts? Please clarify.

Date: 11/9/2005 4:32:18 PM
Author: aljdewey

If you put one drop of red food coloring into an 4-oz glass of water, the color will change significantly....enough for me to notice. If you put one drop of red food coloring into *Lake Michigan*, there IS a measureable, infinitessimal alteration, but not one I can notice or appreciate. There is a difference between a ''measureable difference'' and an *appreciable difference*.

There''s been a lot of discussion recently about stones that score below 1 and how performance in such stones may not perform as well. HOW MUCH less well? Measureable or appreciable? If the difference means I''ll see 20% less light return in a majority of lighting conditions, that would potentially be meaningful to me....and likely appreciable to my eye.

If the difference means that I''ll only see 86.66667676767% light return instead of 86.66667676770% light return, should that matter? I don''t think so.

Good analogy and good point. Answer: Enough of a difference that the 2 most conservative labs don''t consider many of these under HCA
I will reiterate what I said in my last post. The HCA is not a tool for determining Ideal cuts. If a consumer is coming to these boards to try to find what the most conservative labs consider to be the best looking diamonds they will not find it by going to the HCA. As a matter of fact the better the HCA score the greater the possibilities the diamond is going to be a dud and a non ideal.

I''m sorry if I can''t think of a nicer way to say this but this is the God''s honest truth. Not even my own personal opinion. This is AGS and GIA''s opinion so if you want to argue you can take it up with them.

What I see happening on this forum to my dismay (and moreso to Leo''s) is that the HCA is being presented as a tool to identify beautiful diamonds. Yes, yes I know it has been said repeatedly that the HCA is used for an initial screening to *reject* stones but even this is a false dichotomy. Why? Becuase there are stones that score over a 2 on the HCA that are equally (and some would even argue more) beautiful as stones with the highest HCA scores INCLUDING GIA and AGS ideals. Fairly recent we got in a new AGS ideal that scores a 3.1 on the HCA which I am sure will appeal to the tastes of certain people but they would never know about it were they using the HCA.

So if the HCA is going to be purported as a preliminary screening tool my question is "the screening of what exactly?" Because it certainly isn''t for ideal cut diamonds. That fact is established. Curious to hear your input.

Peace,
Jonathan

 

[Rhino]

Date: 11/10/2005 12:30:14 AM
Author: Garry H (Cut Nut)

Date: 11/9/2005 11:42:55 PM
Author: Rhino
Greetings mate,

I realize folks here have been weened on HCA scores and IS images and believe me, I know quite intimately the value of this information but Garry ... we''ve got to dispell the notion that people can come here, plug numbers into the HCA and be led to believe they are getting an ideal cut diamond just because the stone scores less than a 2.

I would make this qualifying statement based on the studies I''ve conducted thus far and I am interested to hear your input of course.
I get tired of saying the same thing - HCA is for rejection, not selection.

GIA:
1. Since new lab reports are not coming until January there is currently FacetWare however there is one metric not covered in Facetware and those would be the effects girdle cutting (painted, digging and classical). So technically if a stone checks fine on Facetware but the upper halves have been painted or dug out the stone would not get ideal rating. To what degree the painting and digging it is is unknown to me at this time. I am sure you ahve all noticed a much larger proportion of stones with painting or digging - so this will be very interesting, and I do not believe the Sarin system accounts for it - as the complexity of proportions is far greater than GIA could have established with 70k observations. I think we are going to witness big huma grading variances because of upper and lower gridle facet treatments from GIA
2. Sarin has released a plug in (a rather expensive one at that) which automatically assigns the GIA grade based on the scan. There is an additional ''recut'' plug in which shows the results of a recut stone guaranteeing GIA Excellent. What''s neat about this is it will also show you the differences in Octonus with that plug in. Very cool. As I have said - Sarin will not guarantee a GIA grade.

But Jon this discussion is not that relevant to the chart above.
You have presumably been searching for well cut BIC''s and FIC''s?

That stone that Brad and Jan posted a year or 2 back (to show that HCA does not work) - that was an excellent example of the type of stone, that if well cut with TLC - then there can be a big range of very attractive stones. Can anyone find a link to it?

I don''t even remember this mate. Please see my prior post Garry. Believe me ... you don''t have to repeat this slogan anymore. "HCA is for rejection, not selection". I''ve heard it so much I woke up saying it.

Just kidding.

The question is ... rejection of what?!?

My educated answer to this question is "Garry''s interpretation of what he considers to be ideal". And franklly there is nothing wrong with that answer. It is my conviction however that John Q. Public, if he is to consult the use of this tool to reject certain diamonds should familiarize himself with your personal preferences Garry. That is all. I think John Q. Public should also be aware of that fact that your personal preferences, in many instances (and even with the new cut grading introduced by both of the most conservative labs) do not agree with your personal opinion either.

Please Garry ... for heaven''s sake don''t take my comments personally. I am doing my best here to keep this strictly from an informational standpoint. If you would like my personal opinion regarding <>2 HCA non ideals/non-ideals I''ll be glad to share it but will not unless asked.

Peace,
Jonathan

 

[valeria101]

Begging to get away from confusion...

Could it be that... if only there were more mundane choices with only the HCA going for them, not all the way AGS and more pedigree, the apparent ''conflict'' or ''confusion'' between HCA and other top grades would melt away?


Choosing by HCA scores among diamonds for which there is a TON more data already can''t help. It even seems odd to put on the same footing based on partial data (HCA input), two choice already told apart by better visual or technical detail. With barely any diamond but AGS0 getting on the list with appropriate numbers, the HCA-cum- meek ''rejection tool'' etc. it never gets to play the part of ''best available'' evaluation for its subjects.

Could this be part of the problem?


Otherwise it is not clear how the HCA-top grade could be confused or appear remotely ''equivalent'' with AGS''s or GIA''s or any other party''s top cut selection.

 

[Rhino]

Date: 11/10/2005 5:18:35 AM
Author: Garry H (Cut Nut)
Belle you are one of the 5% ideal women who can ACTUALLY THINK for yourself. (only 1% of men can think for themselves - see I am not beiong sexist (hang on - that 1% are not ''attached'' to a female - the other 4% of free thinking males do as they are told) )

So does that make you ''ideal'' or ''excellent'' (or a nagging wife / partner?)

Actually, AGS own ''ideal'' in USA.
GIA own ''Excellent''
Since Ideal trumps excellent, AGS has the ''boutique'' position.

LOL. Since I don''t favor either lab but hold them in equal esteem I''d take issue with this comment (not to mention the fact that I am a Vice Prez GIA Alumni here in LI and have friends in both labs).

Now... I''m not picking on anyone mate, so please, once again. The statement could have came from anyone here but would you support this statement?

"A diamond scoring under a 2.0 on the HCA is ideal so there no need to worry about any other details". (these may not have been the exact words but the message was identical, even using the word "ideal").

You indicate in your posts (both here and in the prior thread) that there is nothing wrong with this perspective. Do you support this view mate? You haven''t made any comments specifically on this. Yes or no?

Just as Rhino has moved from 1st best (FS), to better still (LS), to bestest (BS) and on to even betterestest-ever-idealist (ISEE2) - we runs out of superdooper-superlatives.

What did Mary POppins say?

LOL... a spoon full of sugar.

Let me clarify something. Each time our lab acquires a new piece of equipment I try to be careful to point out both strengths and weakness of it. I am for a balanced perspective of them all, including your own technology (the HCA). Naturally I am excited about working with technologies and if I didn''t say I enjoyed the learning and instruction I receive with them I''d be lying. In my postings however you do not see me stressing anyone''s need for it or instilling fear purposely for the sake of instilling fear itself. Yes I realize that it does but let me make it clear that this is not my motives and intent here. My intent is to help people better understand what it is they are getting. That is all. I don''t believe I am stingy with my information and to anyone who asks (at least in email/pm and when I find time here on the forum) I share with anyone the answers to any questions they have on any particular device or diamond inasmuch as I can. You will never find me saying oh no ... don''t buy this or that without consulting this technology first. I have in times past advisesd people to purchase on this forum without knowledge of any of the results of these tools. Truth be told I can do it without any of them. BTW we have acquired yet another new toy. hehe. All I''m saying is just because we make investments to our business, please don''t paint me as purposely instilling fear. I do not operate like that and I do not believe I would not be where I am today if I did. These things help me and I use them solely for the purpose of helping others. I do not see any wrong in that. In summary here ... SURE a person can buy a very nice diamond without any of these tools including the HCA. I''m just a geek for info. That''s all.

Peace,