Why is my ideal cut-I brilliantly yellow in the sun?

[nikonshooter]

Hello everyone,

I recently purchased an engagement ring from a reputable online seller. My intention here is in NO WAY to bad mouth them. I'm just trying to get some information.

I have dealt with them in the past, and I (once upon a time) purchased around a 3/4 carat I VS2 ideal cut from them. It always looked great no matter what the light source was; outside, inside, bright, dark, you name it.

Fast forward to this week, and I received this ring:




The center diamond is an AGS certified .81 / I / VS 1 / Ideal cut diamond. Upon opening initially outside (had just picked it up), the center diamond looked brilliantly yellow in the sun. In most other light it looks good, but the sun makes it explode with full yellow color.

What the heck is going on? Should an ideal cut I diamond with negligible fluorescence light up like the yellow brick road in sunlight? I'm a little disappointed, because if the ring is outside it will be a yellow colored diamond surrounded by smaller diamonds that are brilliantly colorless. I did look around to make sure I wasn't standing by a yellow car or wearing something yellow. It wasn't picking up the color from something around me.

If anyone can help me out, I would appreciate it. I'm not sure what to do with it. I'm not really thrilled with it as it stands.

Thanks!

 

[diamondseeker2006]

Sounds like it could be yellow fluorescence, and I think that sounds AWESOME!!!!! The way to know for sure is to buy a little UV penlight and go into a dark room and see what color the fluorescence is.

Obviously you can exchange the stone, but I would love to see you do the UV light test first!

 

[Circe]

Ditto DS. One "cute" thing GIA does is to occasionally note the strength of the fluor, but not its hue.

 

[chrono]

Should an ideal cut I diamond with negligible fluorescence light up like the yellow brick road in sunlight?

If the fluorescence is negligible as stated in the GIA lab report, it should not be lighting up as obviously yellow under any UV light source. I am stumped.

 

[nikonshooter]

Would you expect a "negligible" fluorescence to react to strongly?

edit: Chrono beat me to it.

 

[Circe]

Should an ideal cut I diamond with negligible fluorescence light up like the yellow brick road in sunlight?

If the fluorescence is negligible as stated in the GIA lab report, it should not be lighting up as obviously yellow under any UV light source. I am stumped.

Actually ... this is something I would LOVE to see explored in a scientific sampling ... I have a thing for fluorescence. To the point that four of the last diamonds I've bought recently have had strong fluorescence, because I've WANTED a stone that turns blue in the sunlight. But no dice ... on any of those four. The stone with the light-to-medium fluor, on the other hand? That one turns perceptibly blue in strong sunlight. Damndest thing ... makes me wonder if there's some additional component to fluorescence being eye-visible aside from strength ... specific wave-length? Anyway, OP, sorry to derail slightly, and back to the topic at hand ....

 

[nikonshooter]

If it lit up blue, I might share your enthusiasm. To me, the yellow glow just makes it look like a much lower color diamond.

As soon as it gets sunny again, I'm going to go outside and take another look. If it continues to light up yellow in the sun, I'm not sure what to do. I already feel a little frustrated that I had to wait over a month to receive the ring. 2 weeks went by, and they let me know they hit a quality control issue and had to start over. The return/replacement process will surely take another few weeks.

 

[Dancing Fire]

Should an ideal cut I diamond with negligible fluorescence light up like the yellow brick road in sunlight?

If the fluorescence is negligible as stated in the GIA lab report, it should not be lighting up as obviously yellow under any UV light source. I am stumped.

Yup, really strange..

 

[HappyNewLife]

My G diamond turns dark grey in the sun, it's so weird too. Can we see a pic of the yellow-in-the-sun phenomenon?

here's what my diamond does (G, no fluor): I was wearing a green shirt, so it was grey-green in the sun that day.

 

[nikonshooter]

Wow! That gray color is unique!

I will try to get a picture if I can. As you can imagine, it's tough being able to get it out for a photo while trying to hide it from my girlfriend. When I can, nature usually laughs at me in the form of rain or overcast.

 

[Harst035]

I would first explore what color fluorescene the diamond emits. If it isn't yellow, I wonder if it's because AGS is purportedly looser on their color standards than GIA is? (so I've read anyway.) I hope you can find a satisfactory and timely resolution– the vendor may expedite any replacement for a repeat customer already frustrated by delays.

 

[Serg]

If it lit up blue, I might share your enthusiasm. To me, the yellow glow just makes it look like a much lower color diamond.

As soon as it gets sunny again, I'm going to go outside and take another look. If it continues to light up yellow in the sun, I'm not sure what to do. I already feel a little frustrated that I had to wait over a month to receive the ring. 2 weeks went by, and they let me know they hit a quality control issue and had to start over. The return/replacement process will surely take another few weeks.

if you wore yellow shirt last test then try white shirt now

 

[Karl_K]

specific wave-length?

It is possible.
Diamonds are tested in the lab under 2 specific wavelengths 1 short-wave and 1 long wave UV.
There are many other wave lengths of UV in sunlight and it is possible for it to react to those and not the ones the lab uses. It is not that common but I have seen a stone that did so and I even had a local jeweler test the stone with a gia approved uv test setup. Next to nothing visible in both long and short.
Next her husband took it to work where they had some UV leak detectors and it turned bright blue under one of them.
The lab uses the ones they do as they are the most common wavelengths diamonds react to but it does not rule out a reaction to others.
More info from Sir John here:
[URL='https://www.pricescope.com/community/threads/wavelength-of-uv-light-for-viewing-fluorescence-in-diamonds.158566/']https://www.pricescope.com/community/threads/wavelength-of-uv-light-for-viewing-fluorescence-in-diamonds.158566/[/URL]

 

[Garry H (Cut Nut)]

specific wave-length?

It is possible.
Diamonds are tested in the lab under 2 specific wavelengths 1 short-wave and 1 long wave UV.
There are many other wave lengths of UV in sunlight and it is possible for it to react to those and not the ones the lab uses. It is not that common but I have seen a stone that did so and I even had a local jeweler test the stone with a gia approved uv test setup. Next to nothing visible in both long and short.
Next her husband took it to work where they had some UV leak detectors and it turned bright blue under one of them.
The lab uses the ones they do as they are the most common wavelengths diamonds react to but it does not rule out a reaction to others.
More info from Sir John here:
[URL='https://www.pricescope.com/community/threads/wavelength-of-uv-light-for-viewing-fluorescence-in-diamonds.158566/']https://www.pricescope.com/community/threads/wavelength-of-uv-light-for-viewing-fluorescence-in-diamonds.158566/[/URL]

The two specific wavelengths used by us gemmo's is based on the two types of frequency that old fluoro tubes could generate.
There is a plethora of other frequencies with more or less impact as Karl says.
There was an excellent review article in Gem & Gemology about 1-2 years ago.

 

[cflutist]

What do AGSL and GIA use today when testing for fluorescence?
Is it still LW 366 nm and SW 254?

 

[Karl_K]

What do AGSL and GIA use today when testing for fluorescence?
Is it still LW 366 nm and SW 254?

hmm found something that makes me question just how they do measure it now:
"On a GIA Diamond Grading Report, fluorescence refers to the strength, or intensity, of the diamond’s reaction to long-wave UV, which is an essential component of daylight. The light emitted lasts as long as the diamond is exposed to the ultraviolet source."

http://4csblog.gia.edu/2012/understanding-diamond-fluorescence

I am going to ping Sir John and see what he knows.

 

[cflutist]

Sir John would know, he seems to know everything.

 

[Garry H (Cut Nut)]

Short wave is only used as a gemstone identification system
(and is dangerous to humans).
Long wave is used for the comments on a grading report.
Many of the LED's also show a fair bit of blue visible light, which can make it hard if you are looking at a fluoro colour other than blue, or a faint blue. But the convenience factor is great for LED's.

 

[arkieb1]

Out of curiosity does it have a greenish grey sort of yellow tint to it? If either of the two stones mentioned above do then maybe they are from Zimbabwe and have an underlying greenish yellowy grey sludgy sort of body tint or under tone to them that shows up more in the sun.

 

[nikonshooter]

If it isn't yellow, I wonder if it's because AGS is purportedly looser on their color standards than GIA is? (so I've read anyway.)

Is there any truth to AGS being looser on their rating standards?

Out of curiosity does it have a greenish grey sort of yellow tint to it?

It does not




Well the good news is that I cannot get it to glow bright yellow anymore. It must have been just those conditions on that day. However, I still feel that in the sunlight I see a tint of yellow or gold. I have asked multiple family and friends, and they cannot see it. I'm either super sensitive to seeing the color, or it's all in my head. The weird thing is that I look up pictures of diamonds that are J-K-L, and this I doesn't show a yellow like those diamonds. It's hard to explain, but it's more of a sharp/golden toned yellow.

Either way, I'm going to propose with the ring as is and then discuss/let my future fiance decide. I've talked to WF about it, and if I decide to return it they will happily expedite a replacement. They have been very helpful! I'm guessing my gf will love it, and it's easy to see why. The ideal cut on this diamond turns out a 1.0 on the pricescope HCA tool. The whole ring is absolutely ON FIRE in low lights like a restaurant. Such a beautiful ring!

 

[Texas Leaguer]

If it isn't yellow, I wonder if it's because AGS is purportedly looser on their color standards than GIA is? (so I've read anyway.)

Is there any truth to AGS being looser on their rating standards?

Out of curiosity does it have a greenish grey sort of yellow tint to it?

It does not

Well the good news is that I cannot get it to glow bright yellow anymore. It must have been just those conditions on that day. However, I still feel that in the sunlight I see a tint of yellow or gold. I have asked multiple family and friends, and they cannot see it. I'm either super sensitive to seeing the color, or it's all in my head. The weird thing is that I look up pictures of diamonds that are J-K-L, and this I doesn't show a yellow like those diamonds. It's hard to explain, but it's more of a sharp/golden toned yellow.

Either way, I'm going to propose with the ring as is and then discuss/let my future fiance decide. I've talked to WF about it, and if I decide to return it they will happily expedite a replacement. They have been very helpful! I'm guessing my gf will love it, and it's easy to see why. The ideal cut on this diamond turns out a 1.0 on the pricescope HCA tool. The whole ring is absolutely ON FIRE in low lights like a restaurant. Such a beautiful ring!

Glad to hear! I had my doubts that the phenomenon you observed was a result of fluorescence. More likely you were seeing an abundance of yellow chromatic flares in that initial viewing environment.

It does raise an interesting question and maybe the experts here would offer their opinions.
Is it possible for a stone to somehow produce unusually high amounts of yellow fire that would give the diamond itself the appearance of being yellow in daylight? Or is it possible that a under specific daylight viewing conditions you would see a higher number or more intense yellow sparkles? And if so, could two diamonds react differently in this respect even if they are both cut to essentially the same ideal specifications?

 

[WinkHPD]

If it isn't yellow, I wonder if it's because AGS is purportedly looser on their color standards than GIA is? (so I've read anyway.)

Is there any truth to AGS being looser on their rating standards?
<SNIP>

According to people that I know and trust, and who submit hundreds of diamonds to both labs (one or the other, not both) and who grade their diamonds to what they expect to receive prior to submitting, there is no truth to that comment.

In fact, in their opinion, AGS with one laboratory is more consistent with their grading than GIA with its many laboratories. They have a Herculean task trying to train and keep hundreds of graders and keep them all on the same page. It is NOT easy.

Both Labs are considered top tier labs because they are the two best labs in the US. I may not like the GIA cut grading system, in fact I dislike it intensely and look forward to when they do a real grading system, but I have heard it again and again from my associates that then they submit diamonds for grading color and clarity that both of them strongly correlate with what they were expecting.

Wink

 

[Karl_K]

Did you clean the diamond between the 2 viewings?

 

[nukezero]

I don't think it should be that yellow.

My GIA J-color with faint fluorescence from GoG is fairly white in outdoor overcast light shown below. I would think your "I" has to be better than this.

 

[nikonshooter]

there is no truth to that comment.

Thanks! I kinda figured they would both be top notch.

 

[nikonshooter]

Did you clean the diamond between the 2 viewings?

I did not.

My GIA J-color with faint fluorescence from GoG is fairly white in outdoor overcast light shown below. I would think your "I" has to be better than this.

Lovely ring! I really only see it in sunlight. Indoors or overcast, and it looks white to me. Like I said, maybe it is just me. I asked several people if they could see a general yellowish tone in the diamond from the side or on top in sunlight. They can't. It could also be, like Texas Leaguer said, that this diamond has a tendency to throw off a yellow color and not so much that it's the I-color of the diamond showing. Maybe it's just my eyes.

When looking at the diamond from the side, should its color be most visible in sunlight? Or, doesn't it matter as long as there is an ample light source?