grading approach for fancy colors vs M-Z round brilliants?

[Rockdiamond]

Re: grading approach for fancy colors vs M-Z round brilliant

Ovi- planning rough is such a complex and intricate task- and when we add the complexities of color, it becomes impossible to make any sort of rules.
Even then, there's many times the cutter can go one way or the other- no "right" answer.
If the person who cut the S-T diamond I referred to above knew what the guy who did the recut knew, we 'd never have seen that S-T diamond.
It was a lovely S-T cushion by the way, but the FY radiant was worth so much more money that there really would have been no choice if the first cuter realized that was an option.

I think there's quite a few "mistake" stones like this floating around the market- more than in colorless IMO

 

[Karl_K]

Re: grading approach for fancy colors vs M-Z round brilliant

Does anyone have a picture of these FC 8-Stars?
I would love to see them.

they were posted on PS at one time but my googlefu is failing me. Maybe someone saved em.

 

[WinkHPD]

Re: grading approach for fancy colors vs M-Z round brilliant

Karl- in my experience, there's no difference in performance or color retention between FCD Cushion and Radiant Cuts. The two designs are both so variable there's plenty of cases where the only difference is the outline of the diamond.
In terms of rounds- it really depends on what the body color of the stone is. Weight retention also plays a role.

We did have a case of an S-T cushion which was damaged during setting the had to be recut.
We lost about 15% of the weight, and the stone re-cut to a Fancy Yellow Radiant.
S-T to FY, it was an amazing transformation.



Wink you saw them in person??
Wow.

Picked them up and played with more than half of them. Put them on my fingers, louped them, lusted mightily after tham...

Wink

 

[diamondhoarder]

Re: grading approach for fancy colors vs M-Z round brilliant

Great link, thanks! Now I cannot wait to read the article and the whole issue and will search for the other articles you mentioned.

It is a very interesting theory that colors are graded based on how attractive they are. I think there has to be some truth to this as most the time I see faint, very light or even light browns being graded on the letter scale and we know that brown in general is not desirable. Yet, when it comes to pinks even very faint pinks will be graded as FCDs, even when the color is hardly discernible.

We also often get grading results where a modifier is not on the report but who decides if a modifier is strong enough to be put on the paper? Many yellows are rarely pure yellows, there is very often a bit of green, a bit of orange and/or a bit of brown, or some or all of the above. I am very color sensitive though and may see something that others do not.

Cool thread on one of my favorite subjects.)

I too have seen barely discernible pinks with a GIA fancy color grading so it's hard to get my head around some of the obviously brown and (IMHO) very attractive stones I have seen recently not being considered worthy of fancy grading. But this may be an advantage - if one of these "undesirable" browns in the S - Z range happens to have the faintest amount of pink in some lights, then it could be a great bargain? Presumably if the main color is considered brown in the S-Z range then GIA would not assign it a modifier in the report? Or would the presence of the faintest pink modifying color automatically propel the brown diamond out of the alphabet grades and into the fancy realm?

 

[Rockdiamond]

Re: grading approach for fancy colors vs M-Z round brilliant

Great link, thanks! Now I cannot wait to read the article and the whole issue and will search for the other articles you mentioned.

It is a very interesting theory that colors are graded based on how attractive they are. I think there has to be some truth to this as most the time I see faint, very light or even light browns being graded on the letter scale and we know that brown in general is not desirable. Yet, when it comes to pinks even very faint pinks will be graded as FCDs, even when the color is hardly discernible.

We also often get grading results where a modifier is not on the report but who decides if a modifier is strong enough to be put on the paper? Many yellows are rarely pure yellows, there is very often a bit of green, a bit of orange and/or a bit of brown, or some or all of the above. I am very color sensitive though and may see something that others do not.

Cool thread on one of my favorite subjects.)

I too have seen barely discernible pinks with a GIA fancy color grading so it's hard to get my head around some of the obviously brown and (IMHO) very attractive stones I have seen recently not being considered worthy of fancy grading. But this may be an advantage - if one of these "undesirable" browns in the S - Z range happens to have the faintest amount of pink in some lights, then it could be a great bargain? Presumably if the main color is considered brown in the S-Z range then GIA would not assign it a modifier in the report? Or would the presence of the faintest pink modifying color automatically propel the brown diamond out of the alphabet grades and into the fancy realm?

This is a phenomenal question.
I have seen stones that were definitely "pink-ish" yet not have the work Pink appear on the GIA report. Unfortunately not all that many
Conversely I've seen plenty of diamonds that had the "P" word on the GIA that showed precious little evidence of why.

 

[Sunstorm]

Re: grading approach for fancy colors vs M-Z round brilliant

Even I have seen a couple that I was sure had some pink in them, a couple were colorless and assigned letter grades but definitely had some pink and then yes a couple browns definitely exhibit pink yet it does not appear on the report. Conversely I have also seen a few examples of pinks when I asked myself why on Earth they were graded pinks. This is strange, if we see pink why do they not see it in the lab? Surely, we are not just imagining that this happens. I know that people work there of course but they have a lot of experience I suppose, now I wonder if most only go through a couple of people and perhaps sometimes not one sees the pink in the stone, I do not know the protocol at GIA.

Since I have been inside HRD I know some about how things work there but I think colorless go through only a couple of graders like two for color, two for clarity and so on, and only if there is a disagreement does a supervisor come in but someone has to decide which stones will be graded on the letter scale and perhaps it is that person in the beginning not noticing the pink and the rest are not even looking for it? Well, correct me if I am wrong. GIA may have a much more complicated procedure in place although I have to say HRD was pretty state of the art, though not sure how good they would be at fancies.

I think that fancies go to GIA period maybe only Gübelin is good at fancies in Europe. Although I have not had an experience with them, I recently considered using them because it is a hassle to send stones to GIA from Europe. I try to get fancies that already have a GIA report but in some cases you end up with something without one that you realize is worth doing a report on.

 

[cflutist]

Re: grading approach for fancy colors vs M-Z round brilliant

I don't suppose you came across one for browns? I tried searching on it through google but no success so far

Today's GIA blog is about brown diamonds:

http://4csblog.gia.edu/2014/bravo-brown-diamonds

 

[hiratop]

Re: grading approach for fancy colors vs M-Z round brilliant

Does anyone have a picture of these FC 8-Stars?
I would love to see them.

https://fbcdn-sphotos-h-a.akamaihd...._=1437405811_09c600b030f23cd6637c063b5f2bb65d
https://scontent.xx.fbcdn.net/hphot...=9c6969c016d87b8206bdd5b4e0abd5bc&oe=55AAE44F
https://fbcdn-sphotos-d-a.akamaihd...._=1437246372_44c09a2e58b075e0d575d36e54a33830
http://www.langerman-diamonds.com/medias/Blog/big/72.jpg
http://www.langerman-diamonds.com/medias/Blog/big/76.jpg
http://www.langerman-diamonds.com/medias/Blog/big/75.jpg