help with cushion

[gemnewbie]

Hi to all and thanks for all the great information in here. Can you please give me your comments on this cushion, please. Also, why does the GIA report say "Old Mine Brilliant" instead of the cushion designation I''ve seen on reports for similar stones? Picture is attached. ASET image to follow when available.

Shape and cutting style: Old Mine Brilliant
Measurements: 7.49x 7.27x 5.00 mm
2.02 ct
G color
SI 1 clarity
Comments: crown angles are greater than 40 degrees

Table: 50%
Depth: 68.8%

 

[Lorelei]

Date: 11/9/2009 11:48:22 AM
Author:gemnewbie
Hi to all and thanks for all the great information in here. Can you please give me your comments on this cushion, please. Also, why does the GIA report say 'Old Mine Brilliant' instead of the cushion designation I've seen on reports for similar stones? Picture is attached. ASET image to follow when available.

Shape and cutting style: Old Mine Brilliant
Measurements: 7.49x 7.27x 5.00 mm
2.02 ct
G color
SI 1 clarity
Comments: crown angles are greater than 40 degrees

Table: 50%
Depth: 68.8%

You sometimes find terms such as old mine brilliant or cushion brilliant used as general categorizations depending on shape but there are variables, what you have there is an old mine / antique or vintage cushion style and it looks like a very lovely diamond - do you have the scan of the report? Do you also have the crown height out of interest from a Sarin report? Be good to see the ASET too when you have it.

 

[pixley]

I''d definitely give that cushion a chance. I looooove the faceting on that stone. My guess is that is was categorized as an Old Mine Brilliant due to the smaller table and perhaps a higher crown. You can ask the vendor if it''s eyeclean to your standards, but it looks lovely to my eyes. Really gorgeous cushion.

Hope the ASET confirms that for you.

 

[FB.]

The stone has lots of potential and is worth pursuing further.

 

[gemnewbie]

Uploaded another image. It''s not great quality, but any thoughts?

Still waiting for ASET and Sarin. Just wondering....how does crown height relate to the table and depth measurements we have, and what would we be looking for as far a crown height in a good stone?

Thanks again for all you help...this is a really great resource for a novice like me

 

[FB.]

Cushions can have frighteningly large crowns, but I suppose that's what was needed "back in the old days" to gather more light.
Angles greater than 40 degrees are often seen, with crown heights of 20% or more.

I have a very nice square-ish cushion, with the following specs:

Table approx: 57%
Stars approx: 65%
Depth approx: 67.7%
Lower halves approx 65%
Length/width ratio: 1.00
Crown angle approx: 41 degrees (crown height approx 24%, if I remember correctly)
Pavilion angle approx: 41 degrees (pavilion depth approx 40% if I remember correctly)
Girdle: slightly thick to thick.

Oh....it's a 1.15ct, D, VS1 with very strong (extreme!) blue fluorescence.

 

[pixley]

Still loving it. The ASET looks great - lots of red in that image.

One of the cut experts can provide you with a more technical explanation, but usually, a smaller table, paired with an overall depth percentage that's on the higher end of the 60s means a higher crown height and likely some nice fire. It reminds me of BostonJeff's cushion, which has a beautiful, high crown. Can't recall the percentage, but you can see from the side shots of his wife's ring.

ETA: Link to BostonJeff's wife's ring photos

 

[gemnewbie]

FB and others, thanks for your input. I just read FB''s other post, in which he advises to pass on "extremely thick" stones. Just went back and read the GIA report, which says that the stone is "medium-extremely thick (faceted)" Any further thoughts?

 

[Hest88]

Gem, the guidance on extremely thick girdles comes mainly because it means excessive weight is around the girdle instead of adding to a wider spread. With the med-ex thick it''s hard to tell how much is med and how much is really thick. Cushion grading is inexact, especially with something that''s supposed to mimic an antique stone like an old mine cut. Since the ASET looks so good I wouldn''t fret so much about the really detailed aspects of the report.

 

[FB.]

Extremely thick is probably allowing the weight to make the 2ct mark. For the cutter to have made it "medium", might have dropped the weight to 1.9ct and a big chunk off his profits.
Apart form the extreme girdle thickness, it seems a good stone. Better an extremely thick girdle than extremely thin (prone to chipping).

Might be worth checking that the extremely thick girdle and steep angles will actually allow safe and secure mounting of the stone in it's setting.

 

[pixley]

Date: 11/9/2009 5:18:00 PM
Author: gemnewbie
FB and others, thanks for your input. I just read FB's other post, in which he advises to pass on 'extremely thick' stones. Just went back and read the GIA report, which says that the stone is 'medium-extremely thick (faceted)' Any further thoughts?

It could be hiding a little bit of weight in the extremlely thick areas of the med-extremely thick girdle. Can you post the Sarin when you get it and the folks can have a look-see. If the crown height is hovering in the 20s, or even the high teens, it wouldn't bother me, personally.

ETA - Ditto FB, I'd also prefer a thicker girdle to an extremely thin girdle as thicker girdles are less prone to girdle chips over a lifetime of wear.

 

[gemnewbie]

Could you please explain how the thickness or the girdle and angles might affect mounting? I was thinking of a Tiffany inspired Legacy setting (with a halo), if that matters.

 

[pixley]

Oooh, a Legacyesque setting would be beautiful. I can''t recall ever reading a thread about thick girdles and setting issues. One of the stones that comes to my mind as a cushion with a high crown and halo, is familystone''s wife''s ring. It''s an antique cushion, a wee bit asymmetrical, with a high crown in a halo setting with a slight airline around the stone. I think it''s magical. The stone you''re looking at appears very symmetrical, so I wouldn''t think you''d have to worry about any strange considerations to compensate for the girdle when it came to setting the stone. I''d love to see that stone in one of Leon Mege''s settings.

Perfection.

 

[Hest88]

Date: 11/9/2009 5:58:52 PM
Author: gemnewbie
Could you please explain how the thickness or the girdle and angles might affect mounting? I was thinking of a Tiffany inspired Legacy setting (with a halo), if that matters.

Lovely choice. You shouldn''t have any issue, I would think, in this case.

 

[Lorelei]

ASET looks great! Crown height, 10% and above.

 

[confusedcushion]

I''ve got another post on here about interpreting ASET pictures for cushions, but I''m reading everything I can about these confusing stones

So, a lot of people like this ASET that''s posted here. Can you please tell me what specifically about the image is good? I see a significant amount of white throughout the image, which I thought was supposed to be bad?

 

[Lorelei]

Date: 11/10/2009 1:02:01 PM
Author: confusedcushion
I've got another post on here about interpreting ASET pictures for cushions, but I'm reading everything I can about these confusing stones

So, a lot of people like this ASET that's posted here. Can you please tell me what specifically about the image is good? I see a significant amount of white throughout the image, which I thought was supposed to be bad?

The image is backlit white and the white you can see through the image is leakage which is where you can see the white backlighting underneath the diamond. However the white in this case should not be an issue due to the way it is dispersed and it is minimal. The image shows a very good amount of red with minimal green and some blue for contrast. What you don't want is where the green is dominant or abundant with little or minimal red.

 

[ChunkyCushionLover]

Date: 11/9/2009 4:15:34 PM
Author: gemnewbie
Uploaded another image. It's not great quality, but any thoughts?

Still waiting for ASET and Sarin. Just wondering....how does crown height relate to the table and depth measurements we have, and what would we be looking for as far a crown height in a good stone?

Thanks again for all you help...this is a really great resource for a novice like me

That ASET image is too difficult to accurately interpret, too much stray background light. I'd get another one to confirm and I would use the filter casing on the handheld or change the backlighting. From looking at the Blue in the 3 - 9 O'Clock Pavillion mains you will see some darkness/obstruction across this region make sure you are willing to accept this.

Judging by the numbers and pictures this looks like a decent cushion. It is not optimized for light return under the the table like the GOG signature Old Mine Cushions but will be at the top end of Cushion Brilliants you will find in the marketplace.

Note on GIA Lab Grading:

First the gemologist must decide on the outline of the stone which is done by eye.
The gemologist has to decide if the outline is round enough or if it has the presence of corners (however rounded) which would make it more cushion shaped.

Historically there are a lot of wonky off round cushions or oval like cushions especially actual old antique cushions (Cut in Late 1800 - Early 1900s) and the only criteria GIA would require to call them a cushion outline is that they have corners no matter how rounded they are. There is some confusion in many threads in this board when an old very rounded looking cushion is presented and the criteria GIA would use would still be done by eye, looking for some sort of pillow(cushion) shape and the presence of corners.

RB= Round Brilliant
OEC= Old European Cut
OMB = Old Mine Brilliant
CB = Cushion Brilliant

So the outline determines if it will be Round (RB Vs. OEC) or Cushion (OMB Vs CB)

To determine in Cushion Outlines if its (CB or OMB)
3 out of the 4 criteria must be true for it is to be called OMB:

i) Table equal to or less than 53%
ii) Culet Equal to or larger than Slightly Large (by visual inspection not by measurement)
iii) Crown Angles Equal To Or Greater than 40 Degrees
iv) Lower Half Length Equal To Or Smaller than 60% (by visual inspection only not by measurement)

The facet plots on GIA reports for cushions ARE NOT meant to represent the actual facets of the stone and are often if not always incorrect especially in old mine cushions/ Cushion Brilliants.

https://www.pricescope.com/community/threads/cushion-halo-setting-now-to-find-the-cushion.127366/page-3

 

[ChunkyCushionLover]

Date: 11/10/2009 5:51:48 AM
Author: Lorelei
ASET looks great! Crown height, 10% and above.

ASET image is not well taken.
Even crappy cushions can have a 10% crown that is not conclusive.

 

[ChunkyCushionLover]

Date: 11/10/2009 1:30:29 PM
Author: Lorelei

Date: 11/10/2009 1:02:01 PM
Author: confusedcushion
I've got another post on here about interpreting ASET pictures for cushions, but I'm reading everything I can about these confusing stones

So, a lot of people like this ASET that's posted here. Can you please tell me what specifically about the image is good? I see a significant amount of white throughout the image, which I thought was supposed to be bad?

The image is backlit white and the white you can see through the image is leakage which is where you can see the white backlighting underneath the diamond. However the white in this case should not be an issue due to the way it is dispersed and it is minimal. The image shows a very good amount of red with minimal green and some blue for contrast. What you don't want is where the green is dominant or abundant with little or minimal red.

You should not be commenting on a poorly taken ASET image and interpreting the dispersion of white as you can't see the contrast properly.

 

[Lorelei]

Date: 11/11/2009 1:56:05 PM
Author: ChunkyCushionLover

Date: 11/10/2009 1:30:29 PM
Author: Lorelei

Date: 11/10/2009 1:02:01 PM
Author: confusedcushion
I've got another post on here about interpreting ASET pictures for cushions, but I'm reading everything I can about these confusing stones

So, a lot of people like this ASET that's posted here. Can you please tell me what specifically about the image is good? I see a significant amount of white throughout the image, which I thought was supposed to be bad?

The image is backlit white and the white you can see through the image is leakage which is where you can see the white backlighting underneath the diamond. However the white in this case should not be an issue due to the way it is dispersed and it is minimal. The image shows a very good amount of red with minimal green and some blue for contrast. What you don't want is where the green is dominant or abundant with little or minimal red.

You should not be commenting on a poorly taken image and interpreting the dispersion of white as you can't see the contrast properly

 

[Lorelei]

Date: 11/11/2009 1:52:55 PM
Author: ChunkyCushionLover

Date: 11/10/2009 5:51:48 AM
Author: Lorelei
ASET looks great! Crown height, 10% and above.

ASET image is not well taken.
Even crappy cushions can have a 10% crown that is not conclusive.

I did not say it was, that a 10% crown height or above was conclusive of a great cushion.

 

[gemnewbie]

I just received a Light Analysis Certificate from GCAL for this stone. I''ve never seen or heard of this type of report before. Unfortunately, I can''t upload it because the file size is too large.

Can you please comment on the value and reliability of this report in general?

The "Light Performance Profile" portion of the report grades the stone as "Excellent" in Optical Brilliance Analysis, and "Very Good" in Optical Symmetry analysis.

In the "Cut Grade" section, the scores were:

Cut---Very Good (80)

Light Performance--Very Good (35) (appears to take lower of Light Performance Profile Scores above)

Finish----Good (20)---(appears to use lower of Polish (very good) and external symmetry (good)

Proportions--Very Good (25)

Additional Information from the diagram not previously available:

Crown and Pavillion Angles: 42.9*/39.5*
Crown Height-23.7%
Pavillion Detpth-41.8%

Looking forward to your comments, please.

 

[Lorelei]

Date: 11/11/2009 6:01:18 PM
Author: gemnewbie
I just received a Light Analysis Certificate from GCAL for this stone. I've never seen or heard of this type of report before. Unfortunately, I can't upload it because the file size is too large.

Can you please comment on the value and reliability of this report in general?

The 'Light Performance Profile' portion of the report grades the stone as 'Excellent' in Optical Brilliance Analysis, and 'Very Good' in Optical Symmetry analysis.

In the 'Cut Grade' section, the scores were:

Cut---Very Good (80)

Light Performance--Very Good (35) (appears to take lower of Light Performance Profile Scores above)

Finish----Good (20)---(appears to use lower of Polish (very good) and external symmetry (good)

Proportions--Very Good (25)

Additional Information from the diagram not previously available:

Crown and Pavillion Angles: 42.9*/39.5*
Crown Height-23.7%
Pavillion Detpth-41.8%

Looking forward to your comments, please.

GCAL offer various certificates, this one is probably an optical brilliance analysis, it would be useful to see it so if you are having trouble posting the image email it to admin using the report concern button and they will post it for you.

 

[penskip]

If you do not buy this stone for some reason, will you let me know ?

 

[Laila619]

Hi,

I'd ask them to re-do the ASET, it's not a great image to be able to really tell. It looks like a nice cushion though!