Comparative Colour

[Buyer35]

I am planning to purchase a stone I saw recently. It's 1.74ct, F, VS2, Excellent cut. However, this is from the Gemscan precert (I am in Toronto). I've read a number of things about Gemscan and there seem to be camps on both sides of the issue. I don't mean to re-raise the reliability of Gemscam again, but here is my question.

This dealer had many diamonds (as dealers do). Some had GIA certs, while others only had GS. What I ended up doing was placing the diamond I selected in a white paper tray which my dealer used to display the colour of the diamonds. He showed me the F stone and also showed me either a G or perhaps a G and an H as well and there was a noticable colour difference at each step. These were all Gemscan stones. I had already eliminated all GIA stones for other reasons (clarity was too high - too expensive, or too low, or size wasn't right), but I asked him to take one of the GIA graded stones which was graded "F" and place it next to the F I had chosen. I could see no appreciable colour difference as to the two stones. My question is, considering I could clearly see the colour difference between the F and the G stones, can I fairly assume that if the GIA stone was certified F that at least the Gemscan cert ought to be correct or at very least no more than one step off from correct? or could there be other factors in terms of stones appearing the same colour but actually being different colours (if you can't see the difference though, who cares?)

The VS2 is obviously more subjective. the only inclusions I could find were a series of 3 or 4 tiny white pinpoint inclusions to the side of the diamond which were entirely unnoticable without a loupe. I get that it's subjective, but I again, having compared this to other stones that were GIA certified, this seems no worse than any VS2 GIA that I'd seen.

Keep in mind that I'm about as far from a professional as possible, but I do like to research when I make a purchase of this size so that I don't just walk in, point to a shiny stone and walk out without knowing what I paid for, so I did look at a lot of stones before choosing one (at a few different dealers), many with GIA certs, and I know somewhat about how the grading and all the criteria work.

The only thing I obviously am at a loss to evaluate are things like
a) the carats - other than comparing the size, I wouldn't be able to assess this, but I understand that weight and measurements are typically the LEAST erroneous info in a non-GIA cert, because it's hard to fudge an objective number
b) more critically, the cut and all the related criteria (cut overall, as well as symmetry, the polish, the finish, the brilliance, the fire, the girdle, the fluorescence, etc.

I obviously want to get a full Gemscan report, not just the precert before I pay for the stone, if for no other reason than to confirm that it IS a diamond (I understand there have been concerns at least in the past, I don't know about today, that GS precerts don't confirm that a diamond is a real diamond), and to confirm things like that the diagram matches the stone.

I guess I'm just looking for some reassurance that I have all my bases covered. I do trust the dealer, as people I know have been dealing with him for a long time, but I am a paranoid person so I am never sure.

This started out as a simple post asking about whether I should trust my eyes in respect of the colour, but as you can see my nerves with this large purchase has turned it into a fairly lengthy ramble!

My two main questions are:
1) Do I trust my comparitive technique with the GIA diamond to confirm the colour is more or less correct?
2) Is there anything I can look for in the full GS report that will tell me if I can trust the excellent cut rating?

Thanks

 

[Black Jade]

I'mnot an expert either.
In the final resort, you need to comfortable;if you are comfortable that the F color is right, I would think you can go with that. HOWEVER, an important point to remember is that you should be paying WAY less for something with a Gemscan cert than for something with a GIA cert.They are just not as reputable and you can't truly trust them for things that only experts can really judge, like inclusions and cut quality and also, if you ever decide to sell (which of course re-selling diamonds you don't get much anyway), the gemscan report will basically be considered like toilet paper and not help you resell at all.
People buy a lot of things with other than GIA and AGS certs and are happy with them, people buy things with no certs and are happy with them, (I have bought diamonds like this myself) but you should definitely not be paying the same price for what is essentially a useless paper and what is the industry standard.
You can use the Pricescope search engine to get some idea of prices,there are GIA diamonds, EGL-USA diamonds (these have some credibility) and no-cert diamonds-- definitely educate yourself about price. It is so easy to get cheated with diamonds as many if not most of the things that make them cost more andnot visible to the naked eye, and not visible even with loupes to non-experts. But that the way it is.
Experts can chime in, as I repeat, I am not one.

 

[Tom Gelb]

I am planning to purchase a stone I saw recently. It's 1.74ct, F, VS2, Excellent cut. However, this is from the Gemscan precert (I am in Toronto). I've read a number of things about Gemscan and there seem to be camps on both sides of the issue. I don't mean to re-raise the reliability of Gemscam again, but here is my question.

This dealer had many diamonds (as dealers do). Some had GIA certs, while others only had GS. What I ended up doing was placing the diamond I selected in a white paper tray which my dealer used to display the colour of the diamonds. He showed me the F stone and also showed me either a G or perhaps a G and an H as well and there was a noticable colour difference at each step. These were all Gemscan stones. I had already eliminated all GIA stones for other reasons (clarity was too high - too expensive, or too low, or size wasn't right), but I asked him to take one of the GIA graded stones which was graded "F" and place it next to the F I had chosen. I could see no appreciable colour difference as to the two stones. My question is, considering I could clearly see the colour difference between the F and the G stones, can I fairly assume that if the GIA stone was certified F that at least the Gemscan cert ought to be correct or at very least no more than one step off from correct? or could there be other factors in terms of stones appearing the same colour but actually being different colours (if you can't see the difference though, who cares?)

The VS2 is obviously more subjective. the only inclusions I could find were a series of 3 or 4 tiny white pinpoint inclusions to the side of the diamond which were entirely unnoticable without a loupe. I get that it's subjective, but I again, having compared this to other stones that were GIA certified, this seems no worse than any VS2 GIA that I'd seen.

Keep in mind that I'm about as far from a professional as possible, but I do like to research when I make a purchase of this size so that I don't just walk in, point to a shiny stone and walk out without knowing what I paid for, so I did look at a lot of stones before choosing one (at a few different dealers), many with GIA certs, and I know somewhat about how the grading and all the criteria work.

The only thing I obviously am at a loss to evaluate are things like
a) the carats - other than comparing the size, I wouldn't be able to assess this, but I understand that weight and measurements are typically the LEAST erroneous info in a non-GIA cert, because it's hard to fudge an objective number
b) more critically, the cut and all the related criteria (cut overall, as well as symmetry, the polish, the finish, the brilliance, the fire, the girdle, the fluorescence, etc.

I obviously want to get a full Gemscan report, not just the precert before I pay for the stone, if for no other reason than to confirm that it IS a diamond (I understand there have been concerns at least in the past, I don't know about today, that GS precerts don't confirm that a diamond is a real diamond), and to confirm things like that the diagram matches the stone.

I guess I'm just looking for some reassurance that I have all my bases covered. I do trust the dealer, as people I know have been dealing with him for a long time, but I am a paranoid person so I am never sure.

This started out as a simple post asking about whether I should trust my eyes in respect of the colour, but as you can see my nerves with this large purchase has turned it into a fairly lengthy ramble!

My two main questions are:
1) Do I trust my comparitive technique with the GIA diamond to confirm the colour is more or less correct?
2) Is there anything I can look for in the full GS report that will tell me if I can trust the excellent cut rating?

Thanks

Hello Buyer 45,

I would voice a few concerns here, but they may not have made any difference. As a color grader there are a couple of things which must be kept as standard as possible if one wants to remain consistent. And two of these things are the environment in which a diamond is viewed and with which geometry. At the GIA they do not use paper trays for a couple of reasons. One is that a lot of them have a strong fluorescent component, and given the fact that the GIA lighting contains some UV the tray could affect a fluorescent diamond differently than a non-fluorescent one. Another reason is that these trays get dirty. Also the angles that diamonds are color graded at is important. Were they viewed face up or face down? At what angle to the light and the viewer? How far from the light source? What type of lighting was used? All of these things especially that last one need to be learned in order to know whether it was done the right way. This is not to say that what you saw was incorrect, but for your comparison to be accurate standardization is vital.

Good luck.