Fancy Light Yellow Diamond with Strong Fluorescence


Jul 28, 2011
Greetings everybody,

I've been browsing this forum and have gained so much information about diamonds; I appreciate the wealth of knowledge and experience/advice offered and I appreciate any insight/suggestions you can make. I'm on the cusp of getting my first (and last) engagement ring and deciding on a stone is proving difficult.

I know there have been several threads discussing colored diamonds with fluorescence and the various positive and negative effects. My girlfriend wants an oval cut, Fancy light or fancy yellow diamond in two tone (prong and basket in yellow gold) halo setting. I'm hoping someone here can direct me to a good appraiser and setting specialist here in Manhattan. Here are the specifics on the stone I'm considering, any insights are appreciated:

Stone Type Diamond
Shape Oval
Measurements 8.53 x 6.44 x 3.36mm
Weight 1.50ct
Color Grade Fancy Light Yellow
Clarity Grade VS1
Cut Grade Very Good
Depth 52.10%
Table 61.00%
Polish Good
Symmetry Good
Fluorescence Strong
Girdle Thick, Faceted
Culet None
Report GIA #5131636863
Retail Price US$11,220.00 (not what they are asking)

I have two concerns with the stone, the first being the shallow depth which may take away from the fire/brillance. The other concern is the strong blue Fluorescence. My mother has a fancy intense yellow with very strong blue fluorescence and she loves it as she says it changes depending on light sources and even appears like a deep yellow in shaded sunlight. I understand with FLY stones the fluorescence can make them appear light or even wash out the yellow color, they have a 30 day return policy so I can buy this ring and send it back. The GIA report checks out and they've provided me with a copy.

My questions for the diamond experts out there are: this a good stone, from the pictures (below) would you purchase this?
2.Should I be weary of the depth percentage and fluorescence?
3.What would be a good price for this stone factoring in the price detriment of the strong fluoresence?
4. If I purchase this where should I bring it in Manhattan (or online) to choose a setting and have it placed, polished, gussied up etc?

Thanks so much for any insight you guys can offer.

fly large.JPG

fly sunlight.JPG


Jun 6, 2011
Where's Kenny when you need him? I'd love to make a longer reply, but the timing is bad. I'll come back to this thread. Welcome to PS! :wavey:

And congrats on choosing to go down the FCD route!


Apr 30, 2005
When a diamond is deep enough the angles of the facets force the light reflect off of, instead of penetrate, the facets near the bottom of the stone.
When the light penetrates the facets you have windowing, which is where you can just see right through the diamond like you can a window.
This is not what you want.
52% depth is pretty shallow and makes windowing likely.

To check for windowing place the diamond above something colored and look for that color under the table.
Often we place a diamond over two closed fingers and look for flesh tone.

It is very difficult to make a call on pricing with FCDs compared to colorless diamonds.
First there are so few FCDs compared to colorless so there is less data.

Next the white diamond color grades, like say G, are very narrow.
Sure nature gives us some Gs that are closer to F and others that are closer to H but ALL Gs are pretty darn close.
Not so with the GIA Fancy Color Grades.
Each grade allows a very wide range of color.
Not only the strength of color but the attractiveness of the hue can vary a great deal too.
This is reflected in the price.
The market has established that brown lowers the price and green increases the price of a yellow.
For these reasons two FCDs that are exactly identical (gradewise on paper) can vary in price a great deal even from the same vendor.
This makes it maddening for customers who want to feel they are getting a good price.

You can do your own research though to get a ballpark idea on pricing. has around 1000 FCDs if you want to see if you can find a comparable one.

It is also difficult to make a call on fluorescence without seeing the diamond.
It can make the appearance better or worse and is a case by case thing.
Plus one owner may like their yellow turing a little green in sunlight and another owner may not.
If you have a vendor you trust ask them to take it out in the sunlight and give their opinion.
Tell them to be honest because if you don't like it you will send it back for a full refund.

You wrote that the cut grade is very good but the report is from GIA.
GIA does not grade cut on FCDs.
Who told you the cut grade was very good and what is that based on?
I would be ver suspicious of a seller who would tell you a 52% deep diamond is very well cut. :Up_to_something:

FCDs are cut to maximize the color and weight so light performance takes a back seat.
I don't blame you for wanting good light performance too, I share your desire when I shop for an FCD.
But it's really tough to get everything in one FCD.
I'm not saying don't try, just letting you know that is not a priority to the industry.


Apr 30, 2005
I did a quick check at
I used their Advanced Search function to find 1.3 to 1.7 ct for Fancy Light Yellow , plus and minus one color grade.

It found 3 that indicate your price of $11,220 is very high.
The bottom one is Fancy Yellow grade, which is one grade stronger yellow and more expensive than your Fancy Light Yellow grade oval.
It's also 1.51 ct but is 27% cheaper.
Also, it has no fluorescence.
I realize it is not oval but it still it gives you some idea about the pricing.

This is exactly why I love prices to be published on the Internet instead of conveyed privately person to person.
Transparency is good for the customer.





Feb 21, 2008
the price is high imo... as far as fluo goes, it's a case by case basis... you have to check with the vendor what effects the fluo has on the stone... depth is also case by case basis... i have a gorgeous shallow pink cushion diamond...

i would actually get that 1.51 FY radiant that kenny linked instead of the oval...


Jan 7, 2009
Hi dankrobinson

Congratulations- It's exciting buying a fancy color diamond!

Fluorescence is kind of a wild card.
In some cases, it's thought GIA is tougher on stones that have it- so that in normal lighting a FLY with Med or strong blue will look darker than an inert FLY.
But sunlight usually has a dramatic effect- in the case of lighter yellow stones with blue they sometimes get very washed out looking in sunlight

In terms of assessing a stone
1)- those in the trade, like me, can't comment on stones of others.
2) Regardless of this, it's not really possible to give an informed opinion with the info provided. There's simply no "right" depth or "wrong" depth
3) Price as well is dependent on so many other factors- so no accurate answer can be given. Personally, my experience, in a broad sense- is that ovals may sometimes be priced a bit lower than cushions or radiant cuts in FLY- but not in all cases
4) the setting is crucial- especially in a lighter color.
I've seen so many nice stones hobbled by poor settings- and fancy colored settings are a specialized skill. I'd also recommend buying stone and diamond from the same vendor so you have someplace to turn if the results are not to your liking. If you get the diamond from one place, and the setting from another, no one is accountable.
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