Diamond Measurement averages?

[find45di2]

Is there a chart that shows the common measurements of a diamond on a carat basis? For instance, the average measurements on a 1.0ct stone? a 1.25ct? a 1.50, 1.75, and so on?

I know that some say that you can get a diamond that has the right measurements and that is cut right and it can sometimes look bigger than its carat weight. Is there a chart or something that shows averages?

 

[Garry H (Cut Nut)]

Just above where you are reading is Pricescope your diamonds

If you search the in-house diamonds for the weights or sizes you want, the number on the right side near the price is the comparitive spread to a Tolkowsky rather ideal stone of the same weight. Most are a smaller -ve spread.

 

[Ellen]

https://www.pricescope.com/community/threads/mm-to-carat-stone-conversion-chart.17578/

 

[Garry H (Cut Nut)]

Date: 9/10/2007 7:51:30 AM
Author: Ellen
https://www.pricescope.com/community/threads/mm-to-carat-stone-conversion-chart.17578/

Those charts are naive and optomistc Ellen. Deduct about .1mm at least.

 

[Ellen]

Date: 9/10/2007 8:08:48 AM
Author: Garry H (Cut Nut)

Date: 9/10/2007 7:51:30 AM
Author: Ellen
https://www.pricescope.com/community/threads/mm-to-carat-stone-conversion-chart.17578/

Those charts are naive and optomistc Ellen. Deduct about .1mm at least.

Gee Gary, we''ve all been using this chart and posting it for others who needed help forever. Why you pickin on me?!

It does note at the top, These are approximate diamond sizes. So, it''s not like they''re written in stone. (pun intended)

I think it helps to give one something to go on. And I''ve found many a stone that fell right where it said it should...But your comment is duly noted. *salutes*

 

[Lorelei]

Date: 9/10/2007 8:37:28 AM
Author: Ellen

Date: 9/10/2007 8:08:48 AM
Author: Garry H (Cut Nut)

Date: 9/10/2007 7:51:30 AM
Author: Ellen
https://www.pricescope.com/community/threads/mm-to-carat-stone-conversion-chart.17578/

Those charts are naive and optomistc Ellen. Deduct about .1mm at least.

Gee Gary, we've all been using this chart and posting it for others who needed help forever. Why you pickin on me?!

It does note at the top, These are approximate diamond sizes. So, it's not like they're written in stone. (pun intended)

I think it helps to give one something to go on. And I've found many a stone that fell right where it said it should...But your comment is duly noted. *salutes*

I have posted this chart a number of times along with Ellen, I shall add deducting about .1mm whenever I post it from now onwards if this may be more accurate.

 

[Jenn5504]

Date: 9/10/2007 8:08:48 AM
Author: Garry H (Cut Nut)

Date: 9/10/2007 7:51:30 AM
Author: Ellen
https://www.pricescope.com/community/threads/mm-to-carat-stone-conversion-chart.17578/

Those charts are naive and optomistc Ellen. Deduct about .1mm at least.

So glad to hear this actually, it has bothered me that my AG000 stone didn''t "measure up" so to speak........

 

[bdawk20]

Not to threadjack here, but I have been researching this as well, as the stone I am looking at seems to have small dimensions for its weight.

GIA cert 1.68 G SI2
Total Depth 61.4
Table 57%
Girdle: Slightly Thick, Faceted
Culet: None

Crown 34deg
Pavillion 40.4

Dimensions: 7.57x7.60x4.66

Looking at these charts and at the pricescope search of in-house stones to check the deviation from ideal spread, this seems really small. Can anybody tell me hy this is? The stone scores 0.8 on the HCA and got a "very good" for spread. Am I wrong in thinking that this is a small spread?

 

[Garry H (Cut Nut)]

Date: 9/10/2007 4:43:21 PM
Author: bdawk20
Not to threadjack here, but I have been researching this as well, as the stone I am looking at seems to have small dimensions for its weight.

GIA cert 1.68 G SI2
Total Depth 61.4
Table 57%
Girdle: Slightly Thick, Faceted
Culet: None

Crown 34deg
Pavillion 40.4

Dimensions: 7.57x7.60x4.66

Looking at these charts and at the pricescope search of in-house stones to check the deviation from ideal spread, this seems really small. Can anybody tell me hy this is? The stone scores 0.8 on the HCA and got a ''very good'' for spread. Am I wrong in thinking that this is a small spread?

Very good on HCA means very good.
It is bigger than a tolkowwsky

 

[Garry H (Cut Nut)]

Date: 9/10/2007 9:00:51 AM
Author: Lorelei

Date: 9/10/2007 8:37:28 AM
Author: Ellen

Date: 9/10/2007 8:08:48 AM
Author: Garry H (Cut Nut)

Date: 9/10/2007 7:51:30 AM
Author: Ellen
https://www.pricescope.com/community/threads/mm-to-carat-stone-conversion-chart.17578/

Those charts are naive and optomistc Ellen. Deduct about .1mm at least.

Gee Gary, we''ve all been using this chart and posting it for others who needed help forever. Why you pickin on me?!

It does note at the top, These are approximate diamond sizes. So, it''s not like they''re written in stone. (pun intended)

I think it helps to give one something to go on. And I''ve found many a stone that fell right where it said it should...But your comment is duly noted. *salutes*

I have posted this chart a number of times along with Ellen, I shall add deducting about .1mm whenever I post it from now onwards if this may be more accurate.

Ladies consider the stoopidity that the dimensions and weights for ovals are the same as emerald cuts for example.

The other round numbers are mostly rather optomistic - they probably work well for 60:60 table depth with very thin girdles.
If you use the method I suggested at the start, you will get a better idea based on real known stones

 

[diamondseeker2006]

Date: 9/10/2007 4:43:21 PM
Author: bdawk20
Not to threadjack here, but I have been researching this as well, as the stone I am looking at seems to have small dimensions for its weight.

GIA cert 1.68 G SI2
Total Depth 61.4
Table 57%
Girdle: Slightly Thick, Faceted
Culet: None

Crown 34deg
Pavillion 40.4

Dimensions: 7.57x7.60x4.66

Looking at these charts and at the pricescope search of in-house stones to check the deviation from ideal spread, this seems really small. Can anybody tell me hy this is? The stone scores 0.8 on the HCA and got a ''very good'' for spread. Am I wrong in thinking that this is a small spread?

Well, my 1.63 stone is 7.6 mm. I am guessing the slightly thick girdle is accounting for some of your weight.

 

[diamondseeker2006]

Here is a chart with visual information:

http://images.amazon.com/media/i3d/01/actual-diamond-size.pdf#search="amazon%20diamond%20size%20chart"

 

[Ellen]

Date: 9/10/2007 4:57:50 PM
Author: Garry H (Cut Nut)
Ladies consider the stoopidity that the dimensions and weights for ovals are the same as emerald cuts for example.

The other round numbers are mostly rather optomistic - they probably work well for 60:60 table depth with very thin girdles.
If you use the method I suggested at the start, you will get a better idea based on real known stones

I have to admit, I always gave it for rounds, I would have no idea on the accuracy of the fancies.

 

[bdawk20]

Not to threadjack here, but I have been researching this as well, as the stone I am looking at seems to have small dimensions for its weight.

GIA cert 1.68 G SI2
Total Depth 61.4
Table 57%
Girdle: Slightly Thick, Faceted
Culet: None

Crown 34deg
Pavillion 40.4

Dimensions: 7.57x7.60x4.66

Looking at these charts and at the pricescope search of in-house stones to check the deviation from ideal spread, this seems really small. Can anybody tell me hy this is? The stone scores 0.8 on the HCA and got a "very good" for spread. Am I wrong in thinking that this is a small spread?

 

[stebbo]

Date: 9/10/2007 5:01:09 PM
Author: diamondseeker2006
Here is a chart with visual information:


http://images.amazon.com/media/i3d/01/actual-diamond-size.pdf#search="amazon%20diamond%20size%20chart"

Again, this chart is optimistic, but as you say, the visually it is good.

Date: 9/10/2007 4:57:50 PM
Author: Garry H (Cut Nut)

The other round numbers are mostly rather optimistic - they probably work well for 60:60 table depth with very thin girdles.

Or 59% depths and below for acceptable girdles. But you won't find too many of those getting AGS0/GIA EX's.

Date: 9/10/2007 4:57:50 PM
Author: Garry H (Cut Nut)

If you use the method I suggested at the start, you will get a better idea based on real known stones

As well as the spread figures Garry suggests, also check out the non-inhouse Pricescope search or any other vendors search and you'll instantly see that majority of 1.0 carat stones (for example) have an average diameter under 6.4mm, although top cuts often sit in the 6.40 - 6.45 range.

Alternatively, check out some search engine like

 

[Lorelei]

Date: 9/10/2007 4:57:50 PM


author: Garry H (Cut Nut)
Ladies consider the stoopidity that the dimensions and weights for ovals are the same as emerald cuts for example.

The other round numbers are mostly rather optomistic - they probably work well for 60:60 table depth with very thin girdles.
If you use the method I suggested at the start, you will get a better idea based on real known stones

Thanks Garry - will do!!

 

[bdawk20]

Sorry about the double post above, hit the wrong button earlier.
Gary, I wasn''t nitpicking on the HCA at all, I think it is an excellent tool. However, I don''t see where it takes the girdle thickness into account, which it seems would be the reason the spread of this 1.68 is more like the 1.63-1.65 stones I am seeing on a pricescope search. Does this make sense of why I am getting a Very Good for spread, but an actual diameter of 7.6-7.56? And more importantly, how much does this matter? I hate the idea of getting a smaller appearing stone as I was originally looking in the 1.75 range, but really like the cut of this one (0.8 HCA, and looks great in person). I guess the question that is germane to this whole thread is how much visible difference does 0.1-0.15mm in diameter make in a round stone?