Uh oh...diamond with very strong fluorescence! Also, cut question.

[blueberrydot]

We just received the GIA report of a loose stone that we are considering. The color is G, and the report indicates that it has a "Very Strong Blue" fluorescence. Should I be worried? I have seen the stone in person and didn''t notice anything odd about it but then again, I didn''t know what I was looking for. Would the "milky" or "oily" appearance that I''ve heard some diamonds with strong fluorescence can have be immediately apparent to the naked eye when one is looking at the diamond?

Also, the stone is graded as a "Very Good Cut" by GIA, and scores a 1.8 on the HCA. However, the table seems to be MASSIVE at 61% - I think I had read on here that tables *should* be around 56% or something? (Forgive me, I''m still a diamond noob

). Here are the numbers I plugged into the HCA:

Depth: 59.8%
Table: 61%
Crown: 32.5
Pavilion: 41

The results:

Light Return: VG
Fire: EX
Scintillation: VG
Spread: EX
Score: 1.8 - Excellent, within TIC range (I have no idea what TIC is, ack!)

My question is, IS the table too big? Would it be worth it to have it recut into Heart and Arrows, perhaps? Would it even be a good candidate for a recut? (It''s a VVS2, so I don''t think durability would be an issue).

Thanks for putting up with all of my pesky questions! This diamond searching has been stressful!

 

[Lorelei]

Date: 12/2/2009 1:14:10 PM
Author:blueberrydot
We just received the GIA report of a loose stone that we are considering. The color is G, and the report indicates that it has a 'Very Strong Blue' fluorescence. Should I be worried? I have seen the stone in person and didn't notice anything odd about it but then again, I didn't know what I was looking for. Would the 'milky' or 'oily' appearance that I've heard some diamonds with strong fluorescence can have be immediately apparent to the naked eye when one is looking at the diamond?

Also, the stone is graded as a 'Very Good Cut' by GIA, and scores a 1.8 on the HCA. However, the table seems to be MASSIVE at 61% - I think I had read on here that tables *should* be around 56% or something? (Forgive me, I'm still a diamond noob

). Here are the numbers I plugged into the HCA:

Depth: 59.8%
Table: 61%
Crown: 32.5
Pavilion: 41

The results:

Light Return: VG
Fire: EX
Scintillation: VG
Spread: EX
Score: 1.8 - Excellent, within TIC range (I have no idea what TIC is, ack!)

My question is, IS the table too big? Would it be worth it to have it recut into Heart and Arrows, perhaps? Would it even be a good candidate for a recut? (It's a VVS2, so I don't think durability would be an issue).

Thanks for putting up with all of my pesky questions! This diamond searching has been stressful!

Apparently if the stone is an overblue with VSB fluorescence you would know it fairly quickly according to one of the experts however I would get an appraiser to check it out to be on the safe side.

Also recutting isn't without risk and not all diamonds are suitable candidates, it might involve a considerable weight loss to have it converted to a h&a cut. Personally I would buy a diamond which is already what you want. Also what is the girdle thickness please? Just to be cautious with that crown angle, if it is very thin then that might be a potential durability issue so if you could find that out it would be helpful. Also the cut is reasonable, not cut to top standards but it could be a very attractive diamond, the table isn't huge also, do you like the diamond as you have seen it in person?

TIC means within Tolkowsky Ideal Cut range.

 

[stone-cold11]

weird, from the numbers it should get a GIA Ex in cut. Can you post the report number and the stone weight?

Ditto Lorelei.

 

[blueberrydot]

Date: 12/2/2009 1:30:52 PM
Author: Lorelei

Apparently if the stone is an overblue with VSB fluorescence you would know it fairly quickly according to one of the experts however I would get an appraiser to check it out to be on the safe side.


Also recutting isn''t without risk and not all diamonds are suitable candidates, it might involve a considerable weight loss to have it converted to a h&a cut. Personally I would buy a diamond which is already what you want. Also what is the girdle thickness please? Just to be cautious with that crown angle, if it is very thin then that might be a potential durability issue so if you could find that out it would be helpful. Also the cut is reasonable, not cut to top standards but it could be a very attractive diamond, the table isn''t huge also, do you like the diamond as you have seen it in person?


TIC means within Tolkowsky Ideal Cut range.

Thanks for info! The girdle is "Medium to Slightly Thick, Faceted (4.0%).

Stone-cold, the GIA number is 2111451231, but I just tried to look it up on the site and it''s not coming up. It was just graded on Nov 30, so perhaps they haven''t updated their system with the report yet.

I''ll copy and paste the "Job Details" of the stone on the GIA website - I believe it includes all the facts that will be in the official version of the GIA report.

Report No. 2111451231
Control No.
Client Ref No.
Job No.
Service(s) Diamond Grading Report,First Inscription, GIA Report Number
Current Status READY FOR RETURN
Report Issued Diamond Grading Report
Report Date November 30, 2009
Invoice No. --
Inscription Registry GIA 2111451231
Shape Round Brilliant
Measurements 8.31 - 8.42 x 5.00 mm
Carat Weight 2.13 carat
Color G
Clarity VVS2
Clarity Status Not Potential
Cut Very Good
Polish Very Good
Symmetry Very Good
Total Depth 59.8%
Table Size 61%
Crown Angle 32.5°
Crown Height 12.5%
Pavilion Angle 41.0°
Pavilion Depth 43.5%
Star Length 60%
Lower Half 85%
Girdle Medium to Slightly Thick, Faceted (4.0%)
Culet None
Fluorescence Very Strong Blue
Comments None
Key to Symbols Pinpoint, Natural
Additional Inscription

 

[Lorelei]

Ok thanks. The diamond also has long lower girdle facets, personally I like this look as it gives a ' splintery' look to any arrows you might see and sharp flashes of light but this is personal preference. The LGF will also account for the VG cut grade. What I would suggest, get an appraiser to check the fluorescence if you like the diamond and make sure you have a good return policy in writing to give you time to do this. Also check out some AGS0 from Jareds if there is one near you or Hearts on Fire brand to view some top cut stones with smaller tables, this will give you a better idea of your preferences. If it turns out more of a 60 60 type stone is what you like then this one could fit the bill providing the fluorescence is proved not to be an issue.

 

[stone-cold11]

ya, probably too soon to be updated in their database. Ok, the lower half is bringing down the cut grade for this stone. Dropping it to 80% will get an Ex cut grade. So nothing really bad for the stone from the numbers on the report.

 

[Laila619]

For a round diamond, that table size is way bigger than I like to see. Check out the cut charts under Knowledge at the top. They give you ranges for ideal crown, pavilion, table, depth, etc.

http://diamonds.pricescope.com/round.asp click!

 

[FB.]

Is the table too large?
Not necessarily. It's overall proportions are quite close to what would be considered a very good "60/60".


Regarding the VSB fluor, I would expect a VVS clarity to be fairly safe and unlikely to turn milky. Many non-fluor stones also turn milky in sunlight - mainly as a result of the type, size and quantity of the inclusions within.
SI or I clarity grades with large clouds and twinning wisps in them seem most at risk of milkiness as a result of the light being bounced around and dispersed in the hazy areas of the stone.
Yet people only speak of cloudiness in VSB or SB fluor stones.

An honest seller will tell you about any haziness if you ask them, and will have a good returns policy if you're not happy.

Am I biased? Maybe - I have several SB or VSB fluor stones.
But ask yourself; would I have that many (and be on the lookout for more at the right price) if they were a problem?

Here's a picture of what VSB fluor can look like in strong daylight. Even VSB stones tend to look colourless like other diamonds under indoor lighting, unless you're near a window with strong daylight coming in.
Make sure that you're comfortable with the way that a VSB can look though. Here's a pic of one of mine which I have posted before - GIA17226269 1.14ct.

 

[Lorelei]

FB, the diamond received VG cut grade because of the length of the lower girdle facets, 85% won't get Ex. I don't know if you have come across GIA Facetware but if not you can use this and enter the info for any diamond to check cut grades.

http://www2.gia.edu/facetware/

 

[FB.]

Thanks, Lorelei.
I hadn''t seen the lower half length at the time of my posting. I''ll edit my earlier reply.
Could be a very good stone, for it''s type. Face-up large and very bright, but some reduction in fire and contrast.

 

[blueberrydot]

Thanks everyone for all the information! I think we will probably be purchasing this diamond. I''m going to have another look at it today. The jewelers have a rather extensive collection of Hearts and Arrows cuts so I''ll definitely do some comparing and figure out what I prefer. Thanks again so much for all your expertise, I feel much more secure about buying this stone now that I have consulted with you all. *hi fives pricescope*

 

[Laila619]

Just be aware that this diamond will lean more towards a bright diamond with white light but not lots of firey flashes or colored light. Good luck!

 

[outatouch0]

Date: 12/2/2009 1:58:29 PM
Author: FB.
Is the table too large?

Not necessarily. It''s overall proportions are quite close to what would be considered a very good ''60/60''.



Regarding the VSB fluor, I would expect a VVS clarity to be fairly safe and unlikely to turn milky. Many non-fluor stones also turn milky in sunlight - mainly as a result of the type, size and quantity of the inclusions within.

SI or I clarity grades with large clouds and twinning wisps in them seem most at risk of milkiness as a result of the light being bounced around and dispersed in the hazy areas of the stone.

Yet people only speak of cloudiness in VSB or SB fluor stones.


An honest seller will tell you about any haziness if you ask them, and will have a good returns policy if you''re not happy.


Am I biased? Maybe - I have several SB or VSB fluor stones.

But ask yourself; would I have that many (and be on the lookout for more at the right price) if they were a problem?


Here''s a picture of what VSB fluor can look like in strong daylight. Even VSB stones tend to look colourless like other diamonds under indoor lighting, unless you''re near a window with strong daylight coming in.

Make sure that you''re comfortable with the way that a VSB can look though. Here''s a pic of one of mine which I have posted before - GIA17226269 1.14ct.

FB,
Very cool pic indeed. Thanks for posting that. I am mulling over getting a blue fl for my wedding band - just to be different. Interesting to see how it reacts to sunlight.

 

[Rockdiamond]

Hi All1

fluorescence is widely misunderstood. Although most cases are no problem at all, the industry discounts D-H color stones with FL.
Personally I love a lot of them

If a stone has an "over blue" fl that turns it milky, you won''t need an expert to let you know- it would be obvious.

In extreme cases yo won;t need sunlight to see the haze- in some lesser cases you will only notice in direct sunlight.

In terms of imperfections, in almost all cases, they have no effect on this aspect.
An IF can be milky, while an I1 can be very crystal like- it all depends on how the fl affects the material of the diamond.

It sounds like it might be a very nice stone blueberrydot!

I would advise never buying a stone like this to recut- if you like how it looks, and the price and deal are good, it may be a winner as is!

 

[blueberrydot]

Date: 12/2/2009 3:44:37 PM
Author: Laila619
Just be aware that this diamond will lean more towards a bright diamond with white light but not lots of firey flashes or colored light. Good luck!

Just so I''m clear, this would be due to the cut of this particular diamond and not fluorescence, right?

 

[stone-cold11]

Date: 12/2/2009 5:45:33 PM
Author: blueberrydot

Date: 12/2/2009 3:44:37 PM

Author: Laila619

Just be aware that this diamond will lean more towards a bright diamond with white light but not lots of firey flashes or colored light. Good luck!

Just so I''m clear, this would be due to the cut of this particular diamond and not fluorescence, right?

Yap, that is due to the cut not the fluor.

 

[FB.]

Date: 12/2/2009 5:45:33 PM
Author: blueberrydot

Date: 12/2/2009 3:44:37 PM
Author: Laila619
Just be aware that this diamond will lean more towards a bright diamond with white light but not lots of firey flashes or colored light. Good luck!

Just so I'm clear, this would be due to the cut of this particular diamond and not fluorescence, right?

As above; it's the angles of the stone's facets that make it look large and bright, but with slightly reduced fire and scintillation. Any stone cut to those proportions would have similar characteristics.
The fluor is just changing the colour of the stone when it is exposed to bright daylight, sunlight, or any artificial light that contains moderate amounts of ultraviolet. Of course, the occasional stone may turn cloudy/milky/hazy too, but most fluors stones don't do that.

Attached is a (borrowed) picture of a SI2 clarity stone with significant twinning wisps/clouds. You can see that the inclusions are reflecting around the stone and are interfering with the correct light passage - causing milky/oily/hazy areas - likely to be more noticeable in sunlight, but may be visible in other lighting conditions.

 

[FB.]

Just found another reasonable picture of mine in sunlight, showing VSB fluor.

 

[blueberrydot]

Date: 12/2/2009 6:37:16 PM
Author: FB.
Just found another reasonable picture of mine in sunlight, showing VSB fluor.

Thanks for the pictures and the explanations!

I have one more question - you mentioned in your first post that the stone I''m considering has proportions approximating a "60/60" - what does this mean? Is that good or bad?

 

[stone-cold11]

60/60 is a round brilliant cut with 60% table and 60% depth. It has a different pattern from a near tolk proportioned stone. Some like it some do not, it is a personal preference thing. Since you saw the stone before, you probably like it. Go and compare it with an AGS0 stone of near tolk proportion and see which you like.

 

[FB.]

Date: 12/2/2009 7:28:28 PM
Author: blueberrydot

Date: 12/2/2009 6:37:16 PM
Author: FB.
Just found another reasonable picture of mine in sunlight, showing VSB fluor.

Thanks for the pictures and the explanations!

I have one more question - you mentioned in your first post that the stone I''m considering has proportions approximating a ''60/60'' - what does this mean? Is that good or bad?

Typical features of a 60/60 compared to a Tolkowsky:

Stones of the same carat weight tend to be shallower, so are wider as a result. They look slightly larger than Tolkowsky ideal stones.
60/60 tends to be a bit of a brighter white than a Tolkowsky. The 60/60 stone generally has less noticeable black/white contrast, less overall flashes (scintilation) and less noticeable coloured flashes (fire), but each flash is larger and seems to flash for longer than a Tolkowsky.
Generally speaking, people who are unsure would be best to go for a Tolkowsky, but there''s nothing especially wrong with a 60/60; it''s just different. I have both. The differences are noticeable and enough to make some people prefer one over the other, but unless someone tells you what to look for to tell the differences, it''s hard for many people to explain why there are actual visible differences and why they like one or the other.