HCA of 0.8 despite a large table?

[stermag]

Hello,

I''m looking at a 1.5carat diamond with the folowing proportions:

Depth: 59.5
Table: 59
Crown: 34.8
Pav: 40.5

These dims give an HCA of 0.8 and a score of "excellent" on light return, fire, scintillation AND spread, however, the table size seems a little large to me, and with that size, the diamond is rated as AGS 1.

I was under the impression that fire often falls victim of large table size, yet the HCA indicates this diamond will have "excellent" fire...

So, what should I think of this one? Dismiss it and keep looking or jump on it (assuming it meets all other criteria on my list).

Thanks in advance.

M

 

[strmrdr]

if it was me id keep looking.
I dont like the angles at all for a ring.

 

[Garry H (Cut Nut)]

AGS ideal can now go to 61% table.

It has a great spread.
I sugest you look if the price and the vendor suit you

 

[valeria101]

Date: 12/7/2005 11:25:40 AM
Author:stermag


I was under the impression that fire often falls victim of large table size, yet the HCA indicates this diamond will have ''excellent'' fire...

Not quite true... but I do remember this being said often and it isn''t wrong either

As far as I know (not much), the fiery looks depends on having light return from some crown facets at lower angles. Depending on all those million angles in a diamond, nothing says that the table size has much to do with it. In practice there is some correlation (diamonds with huge tables are not the most fiery) because large tables often come together with some other odd characteristics (deep pavilion, shallow crown)...

I suspect that the Fire rating of the HCA is based on the prevailing direction of light return. The IS does not show this too well because it does not differentiate zones of high and low angle light return in the visible area (i.e. red under IS). ASET does and there is better, of course. None of the reflector tools are especially good at showing which diamonds would be fiery and which not - but this doesn''t mean it is mission impossible.

All in all, I have no reason to believe that 59% table is ''big'' or that it makes this or any diamond less fiery by itself.


I hope one of the experts will pick this topic up. What happened with the ETAS maps?

-------------------------

About this stone... Well, the HCA may not have been meant to confirm that GAS (or any other cut grades) are ''correct'' or ''wrong'' - it is a tool to understand and compare cut grades across labs and across the ever changing lab grades. The good and the bad about it have been discussed a bunch around here already. However, there isn''t much else out there to allow comparing AGS0, 1, GIA top mid and bottom, seller''s claims and whatever other cut quality claims/results.

In the end, if anything it should work to pic up worthy diamonds that were missed through the gaps of the cut branding and grading systems, as these keep changing their mind. (ie. what happened with the AGS0 of yesterday that are now AGS2-3? how about the AGS7 by former standard that are now AGS0. Who can tell if the system has become wiser and what value the paper has... This is not about AGS, but about cut branding in general, btw.)

Since there is no unique grading system (i.e. AGS does not hold the ultimate truth, neither does any other lab and they keep changing and updating their standards etc.), there must be some good reason to look for some fortunate exceptions to cost-bearing lab paper. To each his own, in this regard.


In the end, I wrote this with the hope to hear a bit of expert advice about ''fire'' and to drop a little hint that you get to see this stone in the flesh

 

[Mara]

seems like it''d be an interesting option. the angles are quite good actually, i''d love to hear what you think of if you see it in person, the table is a bit big and depth a bit small for my personal pref but some vendors swear by 60/60 stones which sounds fairly similar to this with the right angles for the stone, maybe it''s a stunner. HCA score is nice too, it''s so interesting that it got EX in all categories, the HCA is fairly stingy with that final spread EX.

is it virtual or offline? can you post images or more information? idealscope?

 

[Lynn B]

Yeah, I'd LOOOOVE to see that stone, too!

 

[Gonzodogg]

If the table was above 60% I might be concerned - but personally, 59% is so close, if the price is right I would go for it.

 

[stermag]

It was a little quiet here for a while, but I''m so glad you folks have responded. I have a little bit more info and a quick vote, which I hope you will chime in on.

The stone with the slightly wide table (with which I started this thread) has been confirmed to be 100% eye clean. It is said to have three inclusions - a small feather near the girdle, a white pinpoint in the table and a darker inclusion under the crown but none that are detectable with the naked eye. Here is a summary of the specs:

--------------------> STONE #1
Shape: Round
Cut Grade: AGS Excellent 1
Carat: 1.5
Color: E
Clarity: SI2
Depth: 59.5%
Table: 59%
Crown: 34.8
Pav: 40.5
AGS report lists:
Polish: Ideal
Symmetry: Excellent
Proportions: Excellent
- there are no additional comments on the report
- this stone is listed for $7,717.55
- HCA score of 0.8 with EX, EX, EX, EX

Now, another vendor has called in, and is waiting on, a different stone which I was very interested in seeing. Here are its specs/angles:

----------------> STONE #2
Shape: Round
Cut Grade: AGS 0
Carat: 1.525
Color: F
Clarity: SI2
Depth: 61.1
Table: 56.5%
Crown: 34.9
Pav: 40.9
AGS report lists:
Light performance: 0
Proportion factors: 0
Polish: Ideal
Symmetry: Ideal
The AGS report also notes:
- "Additional twinning wisps and surface graining are not shown"
- this stone is listed for $9,670.00
- HCA score of 1.8 with EX, VG, VG, VG

STONE #2 is on its way to a vendor (JA) who will examine it for me and determine whether or not it is eye-clean. Assuming it is, given these differences, particularly the nearly $2000.00 price difference (even though the second stone is still within our budget), which sounds like a better bet?

The way I feel right now, I might just want to see both stones in person, but being that they are coming from two different vendors, I''m not sure if I''ll be able to coordinate comparing these side by side. If I can, this would naturally be ideal. Nevertheless, on paper, which gets your vote and why?

Thank you in advance for your time. You guys are really tremendous to be so generous with your time!

M

 

[Shay37]

For a $2,000 difference, I would have the first stone shipped to an independent appraiser near you and have a look at it. You might be able to have both stones done at the same time. If you could see them together, it would be great. If not, you can certainly see them one at a time. For that big of a price difference, I would have to see that first stone. It could be stellar.

shay

 

[valeria101]

Date: 12/7/2005 4:08:18 PM
Author: stermag


Nevertheless, on paper, which gets your vote and why?


These two are already a select bunch in terms of cut.. so to vote I''d need to see them and see if there is any relation between the 2k and one more sparkle per inch

What may tell these two apart even from a distance is clarity - if both are definitely ''eye clean'' - tough luck. I''d pick up a pair of dice or just remember 2k would help with a very wonderful setting. Otherwise, visible inclusions are rarely preferred...


I don''t know what more to say - without pushing my own personal preferences forth. Between two diamonds I have not seen, this sounds weird even to me.

Side by side pictures from sellers may help for fancies where shape is important, but I suspect that whatever difference between these is way subtle for that. It is still reassuring to see things though

If the two come from the same seller, you could always ask for their opinion. Maybe this sounds silly, but more than once the advice was not at all redundant and not offering just more expensive stuff. They are the only ones with the diamonds at hand, after all.

My 2c, you know

The way I feel right now, I might just want to see both stones in person, but being that they are coming from two different vendors, I''m not sure if I''ll be able to coordinate comparing these side by side.

Obviously everyone would want that, and sometimes it is possible. Either seller may come up with a solution (they may have business partners in your area or something alike). You could also just get both in and inspect them during some return policy, but this is one cash intensive options. Some did it, you may find stories with a search on the forum.



Thank you in advance for your time. You guys are really tremendous to be so generous with your time!

Noooo, well, not me. It is funny that you say this even as a polite end note. Pricescope is a pretty addictive place.

I have no idea why...

 

[Gonzodogg]

my vote is for #1

 

[stermag]

Let me tell you how thrilled I am!!!!!!!!!!!!

It turns out, after digging around, the same vendor who has called in one stone for me (and is waiting for it to arrive) will be able to call the other one in as well! At first it didn''t seem like they were able to see it in the inventory but it is located and on hold for me.

I''m so relieved. Making this decision should be infinitely easer. As Ana suggested, having the seller look at both stones side by side and giving me his/her impression can be tremendously helpful. Plus, the seller is James Allen, and Jim, Josh and Jennifer have been fabulous thus far in the process.

Jim has, on numerous occassions, recommended a cheaper stone over one that was considerably more expensive, which I really appreciate. Of course, back in those days (a mere week or two ago) I knew and understood so little about this process, what to look for and what really matters, that my criteria have all shifted considerably and now I''m obviously looking at something else... (see above).

The biggest shift, for me at least, has been in clarity - I have read posts from so many with SI stones and realized that, while not all SI''s are created equal, they are certainly worthy of consideration and can present incredible value. In my VVS-VS days, we couldn''t look at anything that was much over a carat and now we''re at 1.5! As long as one of these proves eye-clean, I will be a very happy girl.

 

[Lynn B]

Great news! Please be sure to let us know how it goes when you see both diamonds. If you can, please take photos; we would love that! I haven''t been price-shopping for awhile, but man, that first diamond seems like a STEAL of a DEAL! WooHoo!

 

[stermag]

Ana,

You couldn't have been more right - clarity was definitely the distinguishing factor between these two. The less expensive stone looked like an inclusion with a little bit of a diamond around it, as opposed to looking like a diamond with a small inclusion inside it. And this was a stone that the supplier described as "100% eye-clean" - I kid you not, after seeing an idealscope, I think this black inclusion could have been seen from across the room.

That wasn't the only strike against it, but it was the only one I needed to make my decision. We have decided to go with the second stone. It has a feather as its main clarity setting inclusions but the vendor has assured us it does not pose a problem, and it is located on the side, underneath the crown, approaching the girdle, so it isn't easily spotted. We'll have the stone appraised upon its arrival, although I'm wondering if having it appraised in the setting (the vendor is manufacturing a custom setting for us) is going to be problematic? Specifically, will the appraiser be able to accurately asses the risk posed by the feather if it is partially covered by a prong? And if not, should I be comfortable and confident enough of his assessment of the finished ring?

I have received an idealscope of the diamond we're purchasing and although it's not a H&A diamond its symmetry is ideal and the arrows are very well defined (even though they're not as perfect as on H&A stones). I will be sure to post the finished product when it arrives. Thanks for everyone's help.