shape
carat
color
clarity

GIA K color with Very Strong Blue Fluorescence, am I crazy?!

joeq

Rough_Rock
Joined
Sep 30, 2003
Messages
42
Hi all,

I'm in the market for a 4+ carat round brilliant with excellent cut. I previously had a AGS J stone mounted in platinum and never had any issues with the color. Now I found this GIA stone:

Measurements: 10.27 - 10.32 x 6.29 mm
Carat Weight: 4.08
Color Grade: K
Clarity Grade: SI1
Cut Grade: Excellent
Polish: Excellent
Symmetry: Excellent
Fluorescence: Very Strong Blue

Table: 57%
Depth: 61.1%
Crown: 34.5 degrees (15.0%)
Pavilion: 40.6 degrees (43.0%)
Girdle: Medium (faceted) 3.5%
HCA: 1.0 to 1.2

This stone is in my budget ($25K). From the photos, it looks pretty clean from the top. I'll get it in my hands soon so I can look at Idealscope images, H&A, etc.

Am I crazy to drop to K? I have a feeling that due to the cut it will look great from the top, but the color might show through the side, so a bevel setting or a setting that covers the pavilion might be best. I am hoping there is no cloudiness from the fluorescence and it helps to offset the color. But I'm scared that the K grade might have been in light with a UV component and the real color that would show indoor is something like M or N.

What should I watch out for with this stone?

I don't know the provenance but based on the color and fluorescence I'm guessing this stone is from the Premier mine in South Africa.

Also does anyone know a trusted gemologist I could take this to in the CA Bay Area and get a fair opinion?
 

Rockdiamond

Ideal_Rock
Trade
Joined
Jan 7, 2009
Messages
9,170
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

HI Joe, If someone is offering you this stone at $25k, there's a real problem someplace. That's FAR less than the wholesale cost on the stone.
I love a bargain as much as anyone else, but when someone is offering dollar bills for .50cents, there's very likely something bad going on....$25k for that stone is in this category- be careful
 

joeq

Rough_Rock
Joined
Sep 30, 2003
Messages
42
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

Rockdiamond|1446143467|3943520 said:
HI Joe, If someone is offering you this stone at $25k, there's a real problem someplace. That's FAR less than the wholesale cost on the stone.
I love a bargain as much as anyone else, but when someone is offering dollar bills for .50cents, there's very likely something bad going on....$25k for that stone is in this category- be careful

Hi Rock,

Thanks for the feedback. The average retail for 4ct round K-SI1 is $9284/ct according to this. This one is about 30% less than that. What kinds of issues should I be looking for?
- "Overblue", looking milky or cloudy in sunlight
- Inclusions that affect structural integrity
- Misappraised color or clarity
- ???
 

Rockdiamond

Ideal_Rock
Trade
Joined
Jan 7, 2009
Messages
9,170
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

The chart is an average of prices taken from the PS database. These are low retail prices- if you did an average in B&M stores it would be a lot higher.
Then we have a stone being offered at 30% less than an already low list....why?
Likeliest explanation in a SBF stone is a hazy appearance.
The market for 4ct RBC diamonds is not all that weak right now.
So selling so far below "normal" is a big red flag. There's got to be some reason.
 

southLA504

Rough_Rock
Joined
Sep 7, 2015
Messages
78
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

That does seem very cheap, is it a pre-owned stone? That will drop the price.
 

arkieb1

Ideal_Rock
Premium
Joined
May 11, 2012
Messages
9,731
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

Anything that appears to be a bargain is usually one for a reason, if it's not preloved then it being milky or hazy would be my first guess based on price.
 

denverappraiser

Ideal_Rock
Trade
Joined
Jul 21, 2004
Messages
9,043
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

The VSB fluorescence is the issue here. That's making the stone hard for them to sell. Is it justified? Maybe. Some diamonds have an effect called 'overblue' that kicks in with high-UV environments, most notably under direct sunlight. It gives a milky appearance like the obscured glass on a shower door. I"m with the above that this seems decently likely. Even that may be acceptable to you but it's a big problem for diamond dealers. Arrange to look at it first, and specifically arrange to take a peek in direct sunlight when you do.
 

Rockdiamond

Ideal_Rock
Trade
Joined
Jan 7, 2009
Messages
9,170
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

After looking again, I see that there is actually a stone on the market that could be sold for $25k. The particular diamond I'm speaking of is beyond ugly, but is does mean the price is possible.
Most of the stones would sell in the $40k neighborhood on internet sites.
If you do end up getting a great looking stone for $25k it will be a score......let us know what happens!
 

joeq

Rough_Rock
Joined
Sep 30, 2003
Messages
42
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

I'm hoping whatever the issue is it is something I don't care about. I actually like the idea of fluorescence, especially in a low color like K. It would be even better if there is some phosphorescent afterglow. That would make it pretty special!

After 10+ years with a diamond I noticed that in the real world with your naked eye, unless you keep your diamond impeccably clean you would be hard pressed to tell the difference between D and J, or IF and SI2. Hoping if this is an "overblue" that any fogginess is not noticeable, and just serves to improve the color :bigsmile: .

I'll post an update once I actually see the stone.
 

gr8leo87

Shiny_Rock
Joined
Apr 24, 2015
Messages
381
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

As the learned members have indicated there could be 2 reasons for such heavy discounting, these can be location and type of inclusions and fluorescence. It becomes hard to sell if the stone has sizable black inclusions on the table and hazy/milky appearance that hampers the lustre and transparency of the diamond.
 

diamondseeker2006

Super_Ideal_Rock
Premium
Joined
Jan 11, 2006
Messages
58,285
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

What are the inclusions? Are their clouds? Clouds and VSBF may not be a good combination and the reason for the price.
 

joeq

Rough_Rock
Joined
Sep 30, 2003
Messages
42
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

OK, I took a look at the stone in various lighting conditions, and was pleasantly surprised. No real "cloudiness" that I can see. It definitely glows noticeably blue in sunlight. In normal indoor lighting, I am surprised it is rated as a K. In terms of inclusions, there is a lot going on, but nothing black or under the table. The worst is a needle/feather under one of the crown facets.

Here are some shots in bright, direct sunlight. The blue is quite apparent. Some of it is just a reflection from our beautiful California blue sky. But the parts that would normally be black/dark are blue. The redness is a reflection of my red shirt. (I have no idea how you people photograph your diamonds without picking up all the surrounding objects. Do you do it in a white room?)
dsc00248.jpg
dsc00250.jpg
dsc00251.jpg
dsc00253.jpg
dsc00254.jpg

Here us a photo in indirect sunlight. This is much less blue. Doesn't look much like a K, huh?
dsc00264.jpg

Here is an indoor photo under CFL lights (no UV component).
dsc00301.jpg
 

kenny

Super_Ideal_Rock
Premium
Joined
Apr 30, 2005
Messages
31,477
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

joeq|1446620479|3945493 said:
I have no idea how you people photograph your diamonds without picking up all the surrounding objects. Do you do it in a white room?

Not a white room, just some kind of white box.
I use a cloth 'box' or tent that lets light in.



Then you need a hole for the lens to look through.



You can also cut a hole in white styrofoam for the lens to poke through.



Then all you see is the color in the diamond itself, or white if the diamond is white.
Of course there will be some reflection of the black lens.
Even that can be reduced by using a macro lens with a longer focal length, like a 200mm instead of a 60mm.




Oh, and cool pics of a very cool diamond.

_722.png

_723.png

_724.png

99887.png
 

Dancing Fire

Super_Ideal_Rock
Premium
Joined
Apr 3, 2004
Messages
33,852
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

Kenny
A very neat set up.. :appl:
 

kenny

Super_Ideal_Rock
Premium
Joined
Apr 30, 2005
Messages
31,477
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

Dancing Fire|1446624235|3945504 said:
Kenny
A very neat set up.. :appl:

You may throw money, or watches. :mrgreen:
 

Sphene

Brilliant_Rock
Joined
Jan 4, 2015
Messages
666
Re: GIA K color with Very Strong Blue Fluorescence, am I cra

I love it wish I had that luck - let us know how your gona set it :love:
 
Be a part of the community Get 3 HCA Results
    Jewels Of The Week: June 2022
    Jewels Of The Week: June 2022 - 06/24
    Natural Diamond Prices - June 2022
    Natural Diamond Prices - June 2022 - 06/21
    LGBTQ+ Jewelers You Need To Know About
    LGBTQ+ Jewelers You Need To Know About - 06/19
Top