Flourescence makes a huge price difference!

[jyeh74]

Hey folks,

How come flourescence makes that big of a cost difference?
I know most folks say no flourescence is best. But check out what I found
The first has medium and the second has non. Difference of $11k.
Is it worth it to have no flourescence?


http://www.bluenile.com/diamond-search?track=head#diamonds_pid=LD02488577 price is $49k
http://www.bluenile.com/diamond-search?track=head#diamonds_pid=LD02432236 price is $60k

 

[ecf8503]

"worth it"? Well I personally love fluorescence. As long as it doesn't make the stone look oily or milky it is actually a pretty cool effect!

 

[marymm]

I think you may be attributing too much to the fluor in terms of accounting for the price difference between these two stones and not looking to the cut quality difference between the two - as a quick example, the diamond with the fluor also had a 60% table and 58.5% depth - you probably know a table larger than the depth is not generally desirable in a well-cut diamond. I would guess there are also other differences in cut quality but have not run the numbers through the AGA and HCA tools.

 

[TitanCi]

I think it's personal preference. I think it's cool, but the general US consumer market doesn't like it and values ones without, I think. Thus making them less expensive...

 

[bagelboy]

I agree with marymm assessment of cut. In addition look at the inclusion plot, although both are VS-2 people still want and are willing to pay for cleaner looking diamonds. Sometimes even if you can't see the difference, some people still may want the diamond with far less inclusions.

 

[jyeh74]

I think you may be attributing too much to the fluor in terms of accounting for the price difference between these two stones and not looking to the cut quality difference between the two - as a quick example, the diamond with the fluor also had a 60% table and 58.5% depth - you probably know a table larger than the depth is not generally desirable in a well-cut diamond. I would guess there are also other differences in cut quality but have not run the numbers through the AGA and HCA tools.

The first diamond.
60% depth, 58.5% table, 33° crown angle, 40.8° pavilion angle
Light Return Excellent
Fire Excellent
Scintillation Excellent
Spread
or diameter for weight Excellent
Total Visual Performance 1.0 - Excellent
within TIC range

The second diamond.
59% depth, 62.1% table, 35° crown angle, 41° pavilion angle
Light Return Very Good
Fire Good
Scintillation Good
Spread
or diameter for weight Excellent
Total Visual Performance 3.5 - Very Good - Worth buying if the price is right

You stated that a table larger than the depth is not generally desirable in a well-cut diamond, BUT the HCA calculator is telling otherwise. Yes, the $60k diamond does have far less inclusions. But for some reason, both are VS2. I would think that more inclusions (like the first diamond) would have a different clarity grade than less inclusions (the second diamond)

 

[marymm]

OP - I think you reversed the table and depth numbers in the HCA analysis - when I ran numbers I got an HCA score of 1.3 with a Very Good in light return and Excellents in the other three categories. The stone is very close to a traditional 60/60 stone. Its AGA total score is 1B - with a 2A crown angle, 1B in table percent and in crown height, and 1A for the rest.

When I ran the HCA for the 2nd stone, I came up with a score of 2.8 (Very Goods in all 4 categories). It received an AGA total score of 1B (1B for table percent, crown angle, and pavilion depth; and 1A for the rest).

While I still think fluorescence alone does not account for the price difference in these 2 stones, I admit I assumed the AGA scores would reveal more of a difference in cut quality between the two. I believe diamond prices reflect their true market value, and I do not believe Medium Fluor in an H color stone fully accounts for the apx $10k difference between the two stones. You of course may believe differently.

 

[jyeh74]

OP - I think you reversed the table and depth numbers in the HCA analysis - when I ran numbers I got an HCA score of 1.3 with a Very Good in light return and Excellents in the other three categories. The stone is very close to a traditional 60/60 stone. Its AGA total score is 1B - with a 2A crown angle, 1B in table percent and in crown height, and 1A for the rest.

When I ran the HCA for the 2nd stone, I came up with a score of 2.8 (Very Goods in all 4 categories). It received an AGA total score of 1B (1B for table percent, crown angle, and pavilion depth; and 1A for the rest).

While I still think fluorescence alone does not account for the price difference in these 2 stones, I admit I assumed the AGA scores would reveal more of a difference in cut quality between the two. I believe diamond prices reflect their true market value, and I do not believe Medium Fluor in an H color stone fully accounts for the apx $10k difference between the two stones. You of course may believe differently.

Marymm, you are correct. I mixed the depth and table. Can you teach me how to calculate the AGA score and what that represents.

Both stones are VS2 clarity. How come the first stone has so many inclusions while the second stone does not? Thought clarity had to do with how large the inclusions are to the naked eye, not the quantity of inclusions?

 

[yssie]

Both stones are VS2 clarity. How come the first stone has so many inclusions while the second stone does not? Thought clarity had to do with how large the inclusions are to the naked eye, not the quantity of inclusions?

Read both:
[URL='https://www.pricescope.com/community/threads/clarity-grading-question.154174/']https://www.pricescope.com/community/threads/clarity-grading-question.154174/[/URL]
[URL='https://www.pricescope.com/community/threads/is-it-true-that-princesscut-diamonds-are-graded-from-top-not.169988/#post-3090991?hilit=sucks#p3090991']https://www.pricescope.com/community/threads/is-it-true-that-princesscut-diamonds-are-graded-from-top-not.169988/#post-3090991?hilit=sucks#p3090991[/URL]



ETA: nothing wrong w/ either of those stones by the numbers. Screenshot seems to indicate that BN does factor fluor significantly into pricing. Of course there are other factors determining nuances: "secondary" stats, supplier, when the stone was cut, how long it's been in inventory...

 

[marymm]

Here's the PS link to the AGA Cut Class tool - https://www.pricescope.com/tools/AGA_NAJA_Cut_Class_Grader

Here's the PS link that explains the AGA Cut Grading System for Round Brilliants - https://www.pricescope.com/wiki/diamonds/diamond-grading-chart-round

Here's a fairly recent PS thread that goes into a little depth explaining the AGA Cut Class tool - https://www.pricescope.com/community/threads/see-the-new-tool-in-the-tools-section.162390/

Here's a couple good links on Clarity - https://www.pricescope.com/community/threads/does-the-number-of-inclusions-matter.33025/ and also http://www.goodoldgold.com/content.php?c=13

Hope this info is helpful.

(ETA - that BN screenshot Yssie posted is an eyeopener to me - based on that info it does look like across the board BN discounts stones with medium fluor or greater)

 

[jyeh74]

Here's the PS link to the AGA Cut Class tool - https://www.pricescope.com/tools/AGA_NAJA_Cut_Class_Grader

Here's the PS link that explains the AGA Cut Grading System for Round Brilliants - https://www.pricescope.com/wiki/diamonds/diamond-grading-chart-round

Here's a fairly recent PS thread that goes into a little depth explaining the AGA Cut Class tool - https://www.pricescope.com/community/threads/see-the-new-tool-in-the-tools-section.162390/

Here's a couple good links on Clarity - https://www.pricescope.com/community/threads/does-the-number-of-inclusions-matter.33025/ and also http://www.goodoldgold.com/content.php?c=13

Hope this info is helpful.

(ETA - that BN screenshot Yssie posted is an eyeopener to me - based on that info it does look like across the board BN discounts stones with medium fluor or greater)

marymm,

thank you. What is strange is this diamond
http://www.whiteflash.com/loose-diamonds/certificate.aspx?idno=2793558&file_name=1
Scores a 1.4 on the HCA
Light - excellent
Fire - excellent
scintillation - excellent
spread - very good

But on the AGA it scores an overall of 4A

Length:9.24
Width:9.3
Depth:5.79
Total Depth:62.46%
Table percent:54
Crown height:62.5
Girdle (from):Medium
Girdle (to):Slightly thick
Polish:Excellent / Very Good
Symmetry:Excellent / Very Good
Crown angle:35.5
Pavilion depth:40.6

Tab Percent: 1A
Crown Angle: 2A
Crown Height: 4B
Pavilion Depth: 3B
Girdle: 1A
Depth: 1B
Polish: 1A
Symmetry: 1A
TotalGrade: 4A