Please help improve the Carat Weight tutorial

[Garry H (Cut Nut)]

The existing Tutorial is here:
http://diamonds.pricescope.com/carat.asp

Here is a start - please feel free to slander and slash

my pathetic attempt

Carat is the simplest and only truly objective of the four C''s. Pop a diamond on the scales, if it weighs 0.2 gm then it is a 1.00 carat diamond. 1/4ct is often called 25 points.

Everyone knows more Carat weight means more cost. But the surprise is how much more BIG diamonds cost; if you double the weight then the cost is about 4 times more.

The magic 1.00ct D color Flawless costs 1.7 times more than a 99 point or 0.99ct D Flawless. Naturally diamond cutters must achieve the ‘magic weights'', even if that means compromising Cut quality – the sparkle factor.

You might think Carat weight equals size? Wrong! The two diamonds in the picture on the right have the same diameter, and each could be cut from the rough diamond in the centre. But because of the weight of the dull stone on the left it will sell for more than the sparkly one.

It is just so tempting for a cutter to leave a little more weight on the crown and pavilion (the top and the bottom) to push the stone to the next ‘magic weight''. On Pricescope you will learn about tools like HCA and the Ideal-Scope; analysis of stones is often discussed on the Rocky Talky Forum. Make sure you don’t pay for dead weight and get the millimeter spread you are paying for.

The magic weights are 1/2ct, 3/4ct, 90 points, 1ct, 1.5ct, 2ct etc. ‘Under-sizes'' are diamonds that weigh just below a magic weight; they can be a bargain, but there are a lot less to choose from.

The girdle or edge thickness is also important. If a diamond has no girdle, or it is very thin, the stone can have a better spread, but it will chip easily. Medium to slightly thick girdles are safest, but thicker girdles add extra weight or reduce the spread.

To get an idea about the range of spreads for different weights, search the Pricescope vendors in-house diamonds listed and you will see a value next to the price on the far right. Say a 1ct Princess cut is listed at -10% - that means it has the same spread as 0.90ct text book round diamond.

 

[Skippy123]

sounds great and made sense to me; great job!

Maybe something fun to see would be a 1/2, 3/4ths, 1 carat, 1.5 carat, 2 carats, and 2.5 carats all lined up together. People like visuals and it helps people decide what they may want.

 

[strmrdr]

2 things need to be added..
FTC rules for diamond weight and a little about estimated weight if graded mounted by a lab or an appraiser after mounting.
This is a large issue with some IGI and scam ebay labs grading reports where the diamonds are graded mounted which needs to be separated out from an appraiser hired by the consumer using estimated weight.

 

[Garry H (Cut Nut)]

Date: 12/10/2007 12:11:33 AM
Author: strmrdr
2 things need to be added..
FTC rules for diamond weight and a little about estimated weight if graded mounted by a lab or an appraiser after mounting.
This is a large issue with some IGI and scam ebay labs grading reports where the diamonds are graded mounted which needs to be separated out from an appraiser hired by the consumer using estimated weight.

It is international rules, not FTC rules Storm.
You mean :
Diamond weights are rounded up from the third decimal point only when it is a nine.

We need a simple way to describe that
0.995ct = 0.99ct
0.998ct = 0.99ct
0.999ct = 1.00ct

And:
Diamond grading reports list a diamonds weight by the above rules.
However it is legal in some countries, e.g. the USA, to describe a batch of diamond rings as "1 carat rings" even though the diamonds can range from 0.95ct to 1.10ct. In theory the average should be at least 1.00ct. ''Buyer beware'' - especially if the ring comes with an appraisal (with a $ value) and an ''estimated weight'' - that means the diamond was measured in the setting for diameter & depth, and a formula was used to calculate an approximate weight.

That is a bit clunky - but is it what you mean Storm?

 

[Garry H (Cut Nut)]

Date: 12/10/2007 12:00:46 AM
Author: Skippy123
sounds great and made sense to me; great job!

Maybe something fun to see would be a 1/2, 3/4ths, 1 carat, 1.5 carat, 2 carats, and 2.5 carats all lined up together. People like visuals and it helps people decide what they may want.

Excellent idea Skippy - perhaps Andrey could scale it so when you print it they come out actual size?

 

[strmrdr]

Date: 12/10/2007 12:31:32 AM
Author: Garry H (Cut Nut)

Date: 12/10/2007 12:11:33 AM
Author: strmrdr
2 things need to be added..
FTC rules for diamond weight and a little about estimated weight if graded mounted by a lab or an appraiser after mounting.
This is a large issue with some IGI and scam ebay labs grading reports where the diamonds are graded mounted which needs to be separated out from an appraiser hired by the consumer using estimated weight.

It is international rules, not FTC rules Storm.
You mean :
Diamond weights are rounded up from the third decimal point only when it is a nine.

We need a simple way to describe that
0.995ct = 0.99ct
0.998ct = 0.99ct
0.999ct = 1.00ct

And:
Diamond grading reports list a diamonds weight by the above rules.
However it is legal in some countries, e.g. the USA, to describe a batch of diamond rings as ''1 carat rings'' even though the diamonds can range from 0.95ct to 1.10ct. In theory the average should be at least 1.00ct. ''Buyer beware'' - especially if the ring comes with an appraisal (with a $ value) and an ''estimated weight'' - that means the diamond was measured in the setting for diameter & depth, and a formula was used to calculate an approximate weight.

That is a bit clunky - but is it what you mean Storm?

yea something like that...
Where is the rounding point for different labs?
I was under the impression that GIA would give a .995 as 1ct and AGS was .999 was 1ct.
With hrd using the GIA system.

 

[Skippy123]

Date: 12/10/2007 12:32:41 AM
Author: Garry H (Cut Nut)

Date: 12/10/2007 12:00:46 AM
Author: Skippy123
sounds great and made sense to me; great job!

Maybe something fun to see would be a 1/2, 3/4ths, 1 carat, 1.5 carat, 2 carats, and 2.5 carats all lined up together. People like visuals and it helps people decide what they may want.

Excellent idea Skippy - perhaps Andrey could scale it so when you print it they come out actual size?

Yah, that would be great! I know I see that question all the time but something like that would be totally helpful!

 

[Garry H (Cut Nut)]

Date: 12/10/2007 12:41:53 AM
Author: strmrdr

Date: 12/10/2007 12:31:32 AM
Author: Garry H (Cut Nut)

Date: 12/10/2007 12:11:33 AM
Author: strmrdr
2 things need to be added..
FTC rules for diamond weight and a little about estimated weight if graded mounted by a lab or an appraiser after mounting.
This is a large issue with some IGI and scam ebay labs grading reports where the diamonds are graded mounted which needs to be separated out from an appraiser hired by the consumer using estimated weight.

It is international rules, not FTC rules Storm.
You mean :
Diamond weights are rounded up from the third decimal point only when it is a nine.

We need a simple way to describe that
0.995ct = 0.99ct
0.998ct = 0.99ct
0.999ct = 1.00ct

And:
Diamond grading reports list a diamonds weight by the above rules.
However it is legal in some countries, e.g. the USA, to describe a batch of diamond rings as ''1 carat rings'' even though the diamonds can range from 0.95ct to 1.10ct. In theory the average should be at least 1.00ct. ''Buyer beware'' - especially if the ring comes with an appraisal (with a $ value) and an ''estimated weight'' - that means the diamond was measured in the setting for diameter & depth, and a formula was used to calculate an approximate weight.

That is a bit clunky - but is it what you mean Storm?

yea something like that...
Where is the rounding point for different labs?
I was under the impression that GIA would give a .995 as 1ct and AGS was .999 was 1ct.
With hrd using the GIA system.

AGS do not round - they quote 3 dec and let you decide, thx for reminder.
All other labs round up on the .009

So how do we say all that succinctly?

Ira - why don''t you try as an exercise (for our amusement

 

[strmrdr]

Date: 12/10/2007 5:15:54 AM
Author: Garry H (Cut Nut)
AGS do not round - they quote 3 dec and let you decide, thx for reminder.
All other labs round up on the .009

So how do we say all that succinctly?

Ira - why don''t you try as an exercise (for our amusement

ah ok I should have known that brain fart on my part.
dont have any input on wording at this time.
Too much other stuff on my mind + no sleep == RG would do a better job at it.
(just teasing ya bro, keep up the good work!)

 

[Regular Guy]

Hey guys,

A few thoughts (as usual):

1) Re the idea of showing the actual look of diamonds...what is at the upper right is pretty good? On the existing tutorial. Maybe expand it up to 2 carats or more? The piece below it on the upper right is good, too, (on the existing tutorial on the real site), showing how a smaller size can look bigger if well cut. But...I think the numbers got mussed up, and the represented sizes need to be relabeled (i.e., is the ideal cut .84 or .5?).

2) To the question of describing the measure of carats...a) you need to contextualize, and b) find the wording...

a) consider doing this:

Date: 12/9/2007 11:36:49 PM
Author:Garry H (Cut Nut)
The existing Tutorial is here:
http://diamonds.pricescope.com/carat.asp

Here is a start - please feel free to slander and slash

my pathetic attempt

Carat is the simplest and only truly objective of the four C's. Pop a diamond on the scales, if it weighs 0.2 gm then it is a 1.00 carat diamond. 1/4ct is often called 25 points. For the most part (see detail at lower right margin) what you see is what you get.

b) Then, for the detail, I'd make the annotation at the side, keeping the text mostly as is, maybe, but adding a line of perspective, i.e.,

-------------

International standards generally require the recordation of weights to be unrounded, except for the most conservative case, so for example:

Diamond weights are rounded up from the third decimal point only when it is a nine.

0.995ct = 0.99ct
0.998ct = 0.99ct
0.999ct = 1.00ct

Diamond grading reports list a diamonds weight by the above rules

Also, AGS does not round - they quote 3 decimals and let you decide.

However, there is a notable exception. It is legal in some countries, e.g. the USA, to describe a batch of diamond rings as '1 carat rings' even though the diamonds can range from 0.95ct to 1.10ct. In theory the average should be at least 1.00ct. 'Buyer beware' - especially if the ring comes with an appraisal (with a $ value) and an 'estimated weight' - that means the diamond was measured in the setting for diameter & depth, and a formula was used to calculate an approximate weight.

 

[denverappraiser]

Carat is the simplest and only truly objective of the four C's. Pop a diamond on the scales, if it weighs 0.200 gm. then it is a 1.00 carat diamond. A ‘point’ is 1/100 of a carat so 1/4ct. is also often called 25 points or 25pt.

Everyone knows more Carat weight means more cost. But the surprise is how much more BIG diamonds cost; if you double the weight then the cost is about 4 times more.

The magic 1.00ct D color Flawless costs 1.7 times more than a 99 point or 0.99ct D Flawless. Naturally diamond cutters like to achieve those ‘magic weights', even if that means compromising somewhere else, usually cut quality or the sparkle factor.

You might think Carat weight equals size? Wrong! The two diamonds in the picture on the right have the same diameter, and each could be cut from the rough diamond in the centre. But because of the weight of the dull stone on the left it will sell for more than the sparkly one.

It is just so tempting for a cutter to leave a little more weight on the crown and pavilion (the top and the bottom) to push the stone to the next ‘magic weight'. On Pricescope you will learn about tools like HCA, the Ideal-Scope and the ASET that can help you choose. Analysis of specific stones is often discussed on the Rocky Talky Forum.

The magic weights are 1/2ct, 3/4ct, 90 points, 1ct, 1.5ct, 2ct etc. ‘Under-sizes' are diamonds that weigh just below a magic weight; they can be a bargain, but there are a lot less to choose from.

The girdle or edge thickness is also important. If a diamond has a very thin girdle, the stone can have a better spread, but it can chip more easily. Medium to slightly thick girdles are safest, but thicker girdles add extra weight or reduce the spread.

To get an idea about the range of spreads for different weights, search the Pricescope vendors in-house diamonds listed and you will see a value next to the price on the far right. Say a 1ct Princess cut is listed at -10% - that means it has the same spread as 0.90ct textbook round diamond.

Using the GIA grading standards, diamond weights are rounded up from the third decimal point only when it is a nine. These are not the same as the rounding rules you learned in school.

0.995ct = 0.99ct
0.998ct = 0.99ct
0.999ct = 1.00ct

Sometimes carat weight is estimated by using the outside dimensions of the stone. This will be because the grader inspected the stone after it was mounted and they didn’t have the opportunity to use a scale. The top labs won’t do this but often appraisers have to so it depends on who did your grading and when. It should be labeled on your report as ‘estimated’ or ‘approximate’ weight if this has been done and this is approach only accurate to about 5% or so and care should be taken if it’s going to be used for one of these critical weight issues.

Jewelry will often be described in terms of total carat weight, or ctw. This is a sum of the weights of the various stones in the piece. As with the above, often this is approximated as well. 2.00ctw. is very different from 2.00cts. When the headline in the ad says ‘2 carat diamond ring, only $1000!!’, make sure to read the fine print to understand what they mean.

Neil Beaty
GG(GIA) ICGA(AGS) NAJA
Professional Appraisals in Denver

 

[Regular Guy]

Of course, Neil does a more favorable job integrating in the latter half, demonstrating his appropriate stakeholdership, both professional & personal.

 

[Garry H (Cut Nut)]

Thanks guys

Printed to review over cafe''

 

[Garry H (Cut Nut)]

Here is a re edited version with all your contributions added.
Thanks - I think it is looking good.
Note I added the chart below - it came from IDEX and will need a short annotation.



Carat is the simplest and only truly objective of the 4C''s. Pop a diamond on the scales, if it weighs 0.200 gm. then it is a 1.00 carat diamond. A ‘point’ is 1/100 of a carat so 0.25ct is called 1/4ct, 25 points or 25pt.

Everyone knows more Carat weight means more cost. But the surprise is how much more BIG diamonds cost; if you double the weight then the cost is about 4 times more.

The magic 1.00ct D color Flawless costs 1.7 times more than a 99 point or 0.99ct D Flawless. Naturally diamond cutters like to achieve those ‘magic weights'', even if that means compromising somewhere else, usually cut quality or the sparkle factor.

Carat weight equals size? Wrong! The two diamonds in the picture on the right are the same size or diameter; each stone could be cut from the rough diamond. But because of its heavier ‘magic’ one carat weight the dull stone sells for more than the sparkly one.

It is economically tempting for a cutter to leave a little more weight on the crown, girdle and pavilion (the top and the bottom) to push the stone to the next ‘magic weight''. On Pricescope you will learn about tools like HCA, the Ideal-Scope and the ASET that can help you choose wisely. You can post questions about specific stones on the Rocky Talky Forum.

The magic weights are 1/2ct, 3/4ct, 90 points, 1ct, 1.5ct, 2ct etc. ‘Under-sizes'' are diamonds that weigh just below a magic weight; they can be a bargain, but there are a lot less to choose from.
(Add chart)

The girdle or edge thickness is also important. If a diamond has a very thin girdle, the stone can have a better spread, but it can chip more easily. Medium to slightly thick girdles are safest, but thicker girdles add extra weight or reduce the spread.

To get an idea about the range of spreads for different weights, search the Pricescope listed vendors in-house diamonds and look for the value next to the price on the far right. Say a 1ct Princess cut is listed at -10%, that means it has the same spread as 0.90ct textbook round diamond.

International weight rounding is not the same as what you learned in school. Diamond weights are rounded up from the third decimal point only when it is a nine.
0.995ct = 0.99ct
0.998ct = 0.99ct
0.999ct = 1.00ct

Set diamonds cannot be weighed so carat weights are estimated by measuring the outside dimensions of the stone. This means constitutes an appraisal and not a grading report (or ‘cert’) and should state ‘estimated’ or ‘approximate’ weight and an error about 5% is common. (The color will sometimes be given a split grade of say H/I indicating the grade is also an in mount estimate).

Diamond weight in set jewelry is often ‘total carat weight’ or ctw; 2.00ctw of center plus side stones is very different from 2.00cts. It is legal in some countries, e.g. the USA, to describe a batch as ''1 carat rings'' even though the diamonds range from 0.95ct to 1.10ct. In theory the average should be at least 1.00ct. ''Buyer beware''.

 

[denverappraiser]

Date: 12/10/2007 6:20:37 PM
Author: Garry H (Cut Nut)

Set diamonds cannot be weighed so carat weights are estimated by measuring the outside dimensions of the stone. This means constitutes an appraisal and not a grading report (or ‘cert’) and should state ‘estimated’ or ‘approximate’ weight and an error about 5% is common. (The color will sometimes be given a split grade of say H/I indicating the grade is also an in mount estimate).

This is not correct. What makes an appraisal an appraisal is the value conclusion, not the grading methodology. Appraisers can, and often do, produce superb grading results and labs can, and often do, produce nonsense. An estimated weight doesn’t mean that it’s pointless information but it’s important to know that approximate weight and actual weight are saying different things, even when the number is the same.

Check your punctuation. With all of these abbreviations I think you've missed a few periods.

Neil Beaty
GG(GIA) ICGA(AGS) NAJA
Professional Appraisals in Denver

 

[Garry H (Cut Nut)]

Date: 12/10/2007 6:20:37 PM
Author: Garry H (Cut Nut)

Here is a re edited version with all your contributions added.
Thanks - I think it is looking good.
Note I added the chart below - it came from IDEX and will need a short annotation.



Carat is the simplest and only truly objective of the 4C''s. Pop a diamond on the scales, if it weighs 0.200 gm. then it is a 1.00 carat diamond. A ‘point’ is 1/100 of a carat so 0.25ct is called 1/4ct, 25 points or 25pt.

Everyone knows more Carat weight means more cost. But the surprise is how much more BIG diamonds cost; if you double the weight then the cost is about 4 times more.

The magic 1.00ct D color Flawless costs 1.7 times more than a 99 point or 0.99ct D Flawless. Naturally diamond cutters like to achieve those ‘magic weights'', even if that means compromising somewhere else, usually cut quality or the sparkle factor.

Carat weight equals size? Wrong! The two diamonds in the picture on the right are the same size or diameter; each stone could be cut from the rough diamond. But because of its heavier ‘magic’ one carat weight the dull stone sells for more than the sparkly one.

It is economically tempting for a cutter to leave a little more weight on the crown, girdle and pavilion (the top and the bottom) to push the stone to the next ‘magic weight''. On Pricescope you will learn about tools like HCA, the Ideal-Scope and the ASET that can help you choose wisely. You can post questions about specific stones on the Rocky Talky Forum.

The magic weights are 1/2ct, 3/4ct, 90 points, 1ct, 1.5ct, 2ct etc. ‘Under-sizes'' are diamonds that weigh just below a magic weight; they can be a bargain, but there are a lot less to choose from.
(Add chart)

The girdle or edge thickness is also important. If a diamond has a very thin girdle, the stone can have a better spread, but it can chip more easily. Medium to slightly thick girdles are safest, but thicker girdles add extra weight or reduce the spread.

To get an idea about the range of spreads for different weights, search the Pricescope listed vendors in-house diamonds and look for the value next to the price on the far right. Say a 1ct Princess cut is listed at -10%, that means it has the same spread as 0.90ct textbook round diamond.

International weight rounding is not the same as what you learned in school. Diamond weights are rounded up from the third decimal point only when it is a nine.
0.995ct = 0.99ct
0.998ct = 0.99ct
0.999ct = 1.00ct

Set diamonds cannot be weighed so carat weights are estimated by measuring the outside dimensions of the stone. This means constitutes an appraisal and not a grading report (or ‘cert’) and should state ‘estimated’ or ‘approximate’ weight and an error about 5% is common. (The color will sometimes be given a split grade of say H/I indicating the grade is also an in mount estimate).

Set diamonds cannot be weighed so carat weights are estimated by measuring the outside dimensions of the stone. This is normal for an appraisal, which is a report that states the value of an article, but would be wrong for a grading report (or ‘cert’). Such an appraisla should state ‘estimated’ or ‘approximate’ weight and an error about 5% is common. (The color will sometimes be given a split grade of say H/I indicating the grade is also an in mount estimate).

Diamond weight in set jewelry is often ‘total carat weight’ or ctw; 2.00ctw of center plus side stones is very different from 2.00cts. It is legal in some countries, e.g. the USA, to describe a batch as ''1 carat rings'' even though the diamonds range from 0.95ct to 1.10ct. In theory the average should be at least 1.00ct. ''Buyer beware''.

How is that Neil?

 

[Serg]

re:International weight rounding is not the same as what you learned in school. Diamond weights are rounded up from the third decimal point only when it is a nine.
0.995ct = 0.99ct
0.998ct = 0.99ct
0.999ct = 1.00ct


-----------

0.9984ct = 0.99ct
0.9985ct = 1.00ct

 

[denverappraiser]

It''s better, but I still don''t really like it. How about this:

Set diamonds cannot be weighed so carat weights are estimated by measuring the outside dimensions of the stone. This is common for appraisals where the grader is examining a finished piece of jewelry instead of a mounted stone, but would be wrong for a grading report (or ‘cert’). Such a grading should state ‘estimated’ or ‘approximate’ weight and an error of about 5% is common. (The color will sometimes be given a split grade of say H/I indicating the grade is also an in mount estimate).

Neil Beaty
GG(GIA) ICGA(AGS) NAJA
Professional Appraisals in Denver

 

[Garry H (Cut Nut)]

That is good Neil.
Sergey, pleeease!!!

 

[diagem]

Date: 12/11/2007 6:07:51 AM
Author: denverappraiser
It''s better, but I still don''t really like it. How about this:

Set diamonds cannot be weighed so carat weights are estimated by measuring the outside dimensions of the stone. This is common for appraisals where the grader is examining a finished piece of jewelry instead of a mounted stone, but would be wrong for a grading report (or ‘cert’). Such a grading should state ‘estimated’ or ‘approximate’ weight and an error of about 5% is common. (The color will sometimes be given a split grade of say H/I indicating the grade is also an in mount estimate).

Neil Beaty
GG(GIA) ICGA(AGS) NAJA
Professional Appraisals in Denver

Using a formula to estimate rounds is much easier and accurate than fancies..., I think the error % on fancy shapes is quite higher than rounds.

What is common error % on color grading mounted Diamonds? I would think higher??

 

[denverappraiser]

Date: 12/11/2007 10:38:52 AM

Using a formula to estimate rounds is much easier and accurate than fancies..., I think the error % on fancy shapes is quite higher than rounds.

What is common error % on color grading mounted Diamonds? I would think higher??

I agree, +/-5% is doing well. Fancy’s are significantly harder and certain mountings make it far worse. This is the section for describing carat weight, not for assessing the merits and uses of appraisals. That would go under ‘appraiser essentials’ or whatever that gets replaced with. (That’s the portion of the tutorial that I think is in most desperate need of revision). The reason I wanted to include this here at all is because approximate weight and actual weight are importantly different concepts, even when describing the same stone and this does seem like the right place to discuss or at least mention that difference.

Neil Beaty
GG(GIA) ICGA(AGS) NAJA
Professional Jewelry Appraisals in Denver

 

[oldminer]

When I was working on my most recent Journal article I found it confusing to mix the discussion of grading unset stones with the grading of set ones. The same confusion applies to this topic. If you deal first with weighing unset diamonds and then deal with the set diamond topic on its own, maybe things will become more clear to novice readers.

The subject of "total" weight, its use, its abuse, and what it means should be a footnoted item or a link to a page of the things which don''t fit cleanly into the two other discussions. The rounding off of diamonds at .009 stems from two things. 1. Scales used to be less reliably repeatable and accurate. 2. Gravity is not totally identical in every place. #1 is the primary reason for the world''s diamond bourses to have agreed on this unusual scheme for rounding up only at .009. It just saves a lot of headaches when communicating about a particular diamond over a great distance especially at break points like .99ct to 1.00ct.

While I prefer to use the traditional methodology of 0.009 for weight when grading diamonds you''d be surprised at the vast majority of US firms who use the .005 round up methodology. Yes, its legal, but how would you like to buy a .995ct round and pay the 0.999ct premium price for it? Whenever we can, we use .009 rounding on break point diamonds so that the consumer is protected. I imagine I''m not the only one who feels this way about it or takes this step on my own to protect end-users. Since no intelligent retailer pays for 1.00ct when the diamond weight is 0.995, then why should they get to pass it along to the consumer as 1.00ct? "Fairness" means fairness to everyone, not to one party over the other.

 

[Serg]

re:The rounding off of diamonds at .009 stems from two things. 1. Scales used to be less reliably repeatable and accurate. 2. Gravity is not totally identical in every place.

Dave ,
I do not see ANY connection between rules( type) rounding and quality of scales.
you will have same headache for any type rounding.

I see only one reason : 0.95ct diamond is defiantly is not 1.00ct diamond for buyers. 0.99ct looks most close to 1.00. They did same rules( interpolation from 2 signs to 3 signs after point) and receive rule 0.999 ( scale with 4 signs was absent early. It is reason why we did not receive 0.9999 rule)
Then rule 0.9985=0.999=1 came from scale industry ( it is my hypnotize)

 

[diagem]

Serge and David...

You both are taking the one stone 0.95 ct. or 0.99ct. or 0999 ct. example...

I (think) you both are forgetting that rounding is "sometimes" more specific to smaller stones..., (in a plurality combination)
Some/most jewelry pieces will include numerous smaller stones of different size or shapes...,

Take (for example) a ring set with two RB''s of 0.10 cts each + four M/S''s of 0.15 ct. each + four P/S''s of 0.05 ct. each...., what would you guess their combined weight (if you weigh them all together) will be if when you weigh them separately they sum up to a flat 1.00 ct. total weight?

 

[oldminer]

rounding up of single diamonds is internationally accepted at .009. We prefer this.
rounding up of single diamonds is accepted in the USA at .005. It is a weak standard. We use it as necessesary.

rounding up on TOTAL weights of small diamonds to 1 CTW is accepted in the USA from 0.95ct and up. I don''t like it, but that''s the FTC policy. Customers ask us to do it and we do it. It is legal, but not what I''d term a great policy.

Serg: I would never round up a single diamond of 0.95ct to 1ct..... I think there is a misuderstanding or a typo creating a mistake.

 

[diagem]

Date: 12/11/2007 4:41:19 PM
Author: oldminer
rounding up of single diamonds is internationally accepted at .009. We prefer this.
rounding up of single diamonds is accepted in the USA at .005. It is a weak standard. We use it as necessesary.

rounding up on TOTAL weights of small diamonds to 1 CTW is accepted in the USA from 0.95ct and up. I don''t like it, but that''s the FTC policy. Customers ask us to do it and we do it. It is legal, but not what I''d term a great policy.

Serg: I would never round up a single diamond of 0.95ct to 1ct..... I think there is a misuderstanding or a typo creating a mistake.

Maybe in the jeweler to consumer level....

As far as Dealer/cutter to jeweler level..., sorry, I never encountered it!!! On the contrary...., I dont think I ever passed on or sold a 0.999 ct. Diamond as a 1.00 carat Diamond.

I imagine..., once set in jewelry..., thats where this accepted "traditional methodology" is used.

I did hear and know of this "By-Law and Inner Rules" accepted by the WFDB''s..., but I have yet heard of any single dealer buying a 0.999 as a flat 1.00 carat.

 

[oldminer]

The .001 tolerance is built right into the system. The scales in use are no more accurate than that, so many diamonds blessed by GIA as 1.00ct do weigh 0.999ct on some scales. The whole point of the .001 tolerance is to compensate for the level of possible accuracy on the scales in use.

I do think that dealer to dealer sales are still often made with a great deal of honor and integrity not present in other levels of the market. I never had a dealer force me to take a .999ct diamond as 1.00 and I probably would have been very hesitant to have done so anyway. When I pay for 1ct I do not want to take .999ct. Clearly, this has to do with rules and legalities, but not with good business between friendly associates. I feel sure that consumers who are made aware of weight tolerance would prefer full weight stones and not want rounded up weights. I think everyone is entitled to the same benefits.

Let''s ot forget that knowledge is key to getting a fair deal in an open market. Let the buyer beware still has a great deal of meaning.

 

[Garry H (Cut Nut)]

Apart from a size comparison image here is a draft version of the Carat weight page
http://diamonds.pricescope.com/carat2.asp

The distribution chart is real and current - click on it to enlarge it

Edited PS - we will add .5, .7, 1.2 etc on the chart

 

[strmrdr]

Date: 12/14/2007 5:47:32 PM
Author: Garry H (Cut Nut)
Apart from a size comparison image here is a draft version of the Carat weight page
http://diamonds.pricescope.com/carat2.asp

The distribution chart is real and current - click on it to enlarge it

Edited PS - we will add .5, .7, 1.2 etc on the chart

Is an aset page going to be added to the tutorial? thats what i noticed was that ASET wasnt linked like hca and ideal-scope.

 

[Iiro]

http://diamonds.pricescope.com/tutor/availability_carat_distribution_chart_2007.jpghttp://diamonds.pricescope.com/carat2.asp

Thank you Garry again for an eye opening chart. Anyone can see your point immediatly. Cut is second to weight.