Cushion cut Idealscope Help

[Scott Terence]

Hi everyone

,

So I just got my Idealscope/light today and I have been dying to evaluate the light return of two antique cushion diamonds. I will post the images of both IS and magnified photos. I am not choosing between the two but I would greatly appreciate it if anyone could chime in on their merits and faults...

I have noticed from studying the IS of cushions on the GOG site, that there isn't a strict correlation between what one might call a typically "good" IS image and BS metrics... and what is listed as Good, VG, or Excellent light return. Anyone with experience looking at IS images of cushions... maybe Garry H (Cut Nut), Jon (Rhino), or any of the many knowledgeable folk out there might be kind to give their opinions...

And for ease of discussion I shall refer to each stone as A or B.

Thank you very much for all your help,

Scott

pics to follow

 

[Scott Terence]

Cushion A IS

 

[Scott Terence]

Cushion A Pic 1

 

[Scott Terence]

Cushion A Pic 2

 

[Scott Terence]

Now here is the other one:

Cushion B IS

 

[Scott Terence]

Cushion B Pic1

 

[Scott Terence]

Cushion B Pic2

 

[valeria101]

These are such beautiful pictures!

I don't know more about the IS that you do... In these stones, I'd just avoid too much darkness (extinction) and allow some leakage. As far as I can tell, that comes with the model. The IS of the first stone looked pretty good, from this point of view. This is about all I know.

I'd love to wrap these into DC. DO you know any stats (depth, table, crown height) ? This may not work (or not work for me), but if you think it is fun... the results could be posted too.

Thanks.

 

[Scott Terence]

Hi Ana!

Thanks for your kind words sure I have some of the specs:

Cushion A -
1.15 cts
Depth % 74.6
Table % 50.0
6.19 x 5.86 x 4.37

Cushion B -
1.54cts
Depth % 62.6
Table % 58.0
7.46 x 6.46 x 4.36

Sorry no Crown/Pavillion angle info. But I would LOVE to see what kind of modeling you could do with DC. Thanks so much.

Best regards,
Scott

 

[valeria101]

Diamond ''A'' was easier to deal with because the pictures are better and the stone more symmetrical itself. Because of symmetry, I wouldn''t try the other.



Allot of disclaimers...

Firstly, if anyone can do a fair evaluation of diamonds like this, I am not the one. This is not precise in many ways I can tell, and probably in many that I can''t

I''ve tried the same with ASET images of an 8* a few days ago (the wireframe fittings should be on an older thread) and some structural flaw came up - image distortions that I have not worked out. Also, the model used is a perfectly symmetrical square distortion of a RBC. The placement of facets fits, of course but the size of them does not fit perfectly (see the upper girdle facets in particular). This could be addressed but it would be quite a bit of work for me... and did not happen.

Other than this, the process went as follows: fitting square deviation, table, depth, star and lgf. than pin down all these and fit double reflections on your pictures and the main features of the IS by small steps of crown vs pavilion trade offs. In doing this in the IS view, a small neighbourhood of angle measurements produced reflectors across the small diameter (as in your IS) and happened to fit reasonably well the culet reflections through the star facets. The resulting GA file is attached below.


Quick Q - is either light yellow in person?

 

[Garry H (Cut Nut)]

They will be very bright stones for old cuts - but not as scintillating / multitude of smal sparkles etc as a modern round or especially a princess cut.

You obviously have a good collectors eye Scott.

 

[Scott Terence]

Thanks Ana,

Will check it out in depth tomorrow. As for the color, Cushion A is an L with SBF (so tinted a bit) and Cushion B is def light yellow and when exposed to UV due to its SBF, it changes to that electric green-yellow

 

[Garry H (Cut Nut)]

fyi
http://www.ideal-scope.com/manuf_fine_tuning.asp

 

[Scott Terence]

Thank you so very much Garry!

I read your tutorials again and again trying to make sure I knew what I was seeing. The amazing part is that I just picked them with my eyes and trusty loupe (old 10x microscope eye piece). I guess looking at all the diamonds here and at the vendors'' sites pays off

 

[valeria101]

Date: 12/15/2005 4:55:50 AM
Author: Scott 00

Cushion B is def light yellow and when exposed to UV due to its SBF, it changes to that electric green-yellow.

All fancy colors are special.. the old cut ones twice that! Good for you!

 

[Scott Terence]

I just tried out the GA file you posted! I am very very impressed at how close you can get to the real thing with a few pics and clever thinking/software. Thanks so much, I will def be playing with it tomorrow.

One more tidbit about the stones, the vendor specializes in antique cut diamonds and when i went to look at stones, I was informed that infact its not just the cut that is antique but that the stones are each over 100yrs old (in their cut form, obviously older as diamonds perse).

 

[belle]

great pics scott

if you are not choosing between them, does that mean they are both yours?

 

[Scott Terence]

Hi Belle,

One is for me and the other is for my mom, but we were willing to return either/both if something was terribley amiss I am lucky in that I live in NYC so it is not too difficult to look at these in person... and now with the IS in hand, I''ll have even more confidence.

 

[belle]

i love them both! which is which? and what will you be doing with them? such beauties they are!

 

[Scott Terence]

Thanks for much for you kind words Belle!

So far, it is looking like Cushion A (the more symmetric, whiter one) is probably going to be for my mom. And the light yellow Cushion B (graded N but to my eye looks more like an X-Z) is likely to be mine.

We both like strong fluorescence and in the case of Cush A, it makes it a very pleasant whitish appearance. In the case of Cushion B, its really, really obvious when the UV is in the light since the stone takes on this electric neon appearance, like its plugged in to a socket! To my eye its like having a color changing diamond, so I am pretty pleased

For the setting, I am looking into getting a Cartier inspired ring with bead set rounds (4 per side) for my mom's ring. I figured that it will have the understated and refined elegance that the the antique cushion embodies. I'll enclose some pictures from Engagementringsdirect.com (where I am planning on having the ring made/set, someday in the future). I'd appreciate any feed back on that or the stones themselves

Best regards,
Scott

PS I must admit here that its is REALLY hard to find strongly fluroescent diamonds online, I guess people are too scared of them, but I sure did have a blast sorting through the selection at the vendor, this is one great, albeit $$$ hobby

I would also like to thank Carrie from Dirt Cheap Diamonds for being so accomodating and helpful with all my questions about these gems! I very much enjoyed the experience and I would not hesitate to do so again in the future.

 

[Scott Terence]

And here is the top view

 

[Scott Terence]

Oh and the only reason we are still not sure which is for whom is because I had originally wanted an Asscher type cut, I have become such a facet pattern enthusiast, and Cushion A has such a beautifully obvious pattern with all the neat virtual facets, that I like it alot too. Whereas my mom also likes the exotic look of the yellow and disorganized pattern.

Well since we''re still paying off the stones, we will be happily planning the settings for a while. Any suggestions would be welcome...

 

[belle]

they are both such gorgeous stones, but i'll have to admit..i am drawn to 'a' more because of the distinctive cross pattee' pattern it shows

i like the simplicity of the setting you choose, but i think it looks very engagement-y...is that the look she wants?

 

[belle]

what do you think of this?
(too far from understated?)

 

[Scott Terence]

Hi Belle,

Wow that setting sure is, ornate and fitting for the stone. Originally I had envisioned one of the now ubiquitious pave halo settings but they are rather costly and as it turned out, not something my mom likes.

She works in the medical field and often wears gloves, so she prefers the more streamlined look. And as far as how it looks like an E-ring, yeah she does not mind since it is likely that the new ring will be replacing hers

I kind of got the ball rolling when I gave her a 3-stone as a present last summer, since she has gone without any significant diamonds during her life til this time, I guess there were always mouths to feed and bills to pay.

Any other suggestions would be great!

Best,
Scott

PS the pattern is so obvious that it is unmistakeable even at arms length, a pretty neat effect I have to say

 

[Spartan]

Well, I don''t know anything about Cushion cuts. But, I just wanted to chime in and say that you have exquisite taste, Scott.

 

[Scott Terence]

Hi SG,

Thanks a bunch for your kinds words, I just hope that after all is said and done that my mom likes the final product. This site sure "enables" this expensive hobby, but I wouldn''t have it any other way

 

[Scott Terence]

On another note, these stones exhibit strong blue fluorescence... would any one know where the cut off is on the color scale when even SBF can''t negate the tint from the yellow series diamonds. Cushion B was graded as an N but seems far more yellow than that in reality and as I mentioned previously, the SBF imbues it with a neon green/yellow hue (which I like). But even in the Cushion A (graded L), while it appears to mask more of the yellow tint, I have found under close inspection that strong sunlight (presumabley with more UV content) pushes the effect so that the stone also takes on a very very slight green hue.

I would have anticipated that yellow + blue = green but the general consensus on the board was that the blue "masked" or negated the yellow. Any insight into this phenomenon would be appreciated

 

[valeria101]

From your description... could it be that the fluorescence of the yellow cushion is not blue but green or greenish yellow?


I don''t know where the balance between body color and fluorescence would be. What if the UV composition of the light changes? Besides, the blue glow is not just a change of body color. It would be interesting to see what happens if you put these stones under UV light under normal lighting. I wonder if this is what has been done in the glowing pictures HERE (see attached).

And speaking of settings - how about yellow gold for the yellow diamond?

 

[Scott Terence]

Hi Ana!

You and I think very similarly

I have recently been dreaming of a very yellow gold bezel/prong basket for the yellow Cushion B to enhance its apparent tone. Also I am considering mokume gane for the shank if i can get a yellow and green gold mix... so that whatever light the stone is in, it will have a color complimentary "home", what do you think of that idea?

Honestly, at the moment I do not have access to long/short UV sources so I cannot confirm the lab report stating the strong blue fluorescence... but I sure am wanting to do it very soon! And as soon as I do, I will try my best to photograph it for this thread. Thanks for your insight and suggestion.

Maybe if we're lucky David (DBL) will share how he takes those pretty fluor pictures...