Need help on these two stones..

[scotpot]

Assuming no difference in price,... which one would you go for .. and why ???!!


1.
Shape and Cut: Round Brilliant
Measurements: 6.98 x 7.01 x 4.31
Carat Weight: 1.29 ct
Color Grade: G
Clarity Grade: SI2
Cut Grade: AGS Ideal
Table Diameter: 55%
Crown Height: 15.9%
Crown Angle: 35.2
Pavilion Depth: 42.6%
Pavilion Angle: 40.6
Culet Size: pt
Girdle Thickness: 1.1% to 2.0% Faceted
Finish: Ideal
Fluorescence: Negligible
(Additional clouds not shown)

2.
Shape and Cut: Round Brilliant
Measurements: 7.02 x 7.04 x 4.26
Carat Weight: 1.26 ct
Color Grade: H
Clarity Grade: SI2
Cut Grade: AGS Ideal (H&A)
Table Diameter: 56%
Crown Height: 15.2%
Crown Angle: 34.8
Pavilion Depth: 43.1%
Pavillion Angle: 40.9
Culet Size: pt
Girdle Thickness: 1.0% to 1.4% Faceted
Finish: Ideal
Fluorescence: Negligible
(Surface graining not shown)

 

[pqcollectibles]

Strictly based on the info given (disclaimer intended), I'd lean toward the 1.26 ct, H, SI2. Girdle thickness is much better. Also, the H would be the better value. Based on comparing PS Price Stats, if both stones are identically priced.

If you could post crown and pavillion angles, that would be a big help.

 

[scotpot]

Crown & Pavilion Angle added to original post.
Note : 1.26 is H&A

 

[Mara]

The second one: 1.26c. The crown and pav angles are better, girdle is a bit better. Hence, note that the diameter of the 2nd stone is actually BIGGER than the first stone, and depth is less. That means that more of the diamond's weight is visible UP TOP where people's eye can see it, rather than lost in the depth and girdle, as with the first stone.




So in essence you would be getting a lesser carat weight for the 2nd, but it looks bigger than the first. Plus the 2nd is H&A which if the price were the same...coupled with all the other things I noted, would be enough for me. The G to H difference does not matter IMO...I have seen super white H's and my G is white as well. In this instance I would go for better cut. Do you have IdealScope images of both stones? That may be a decision maker...if one has significantly better light return.

 

[Garry H (Cut Nut)]

I would want to have an opinion on the clarity.

About 10% of SI2's make me happy.
An sI3 grade would make sense because so many diamonds that would have been I1 a decade ago are SI2 today.

 

[pqcollectibles]

The G scores a bit better on the HCA.

G - 1.0 TIC Ex/Ex/Ex/Vg

H - 1.6 TIC Ex/Vg/Vg/Vg


Good point, Garry!

Have you seen either/both of the diamonds? How do the clarity plots look? What about the additional clouds not show comment? Get magnified pics of the inclusions if possible on both diamonds.

 

[aljdewey]

I agree with the crew......definitely the H stone as long as both are eyeclean.




The H has more desirable angles, a better girdle, and as Mara mentioned, it shows it's weight in diameter much better than the G stone does.

 

[Stephan]

The G has more desirable angles, as said pqcollectibles, if we believe the cut adviser.

 

[scotpot]

So... one person points out that the G has a more desirable HCA,... and a few say the H has preferable angles. I'll take on board the points about the girth, spread and the clarity. Unless someone tells me otherwise, I'm going to assume that the difference in the HCA scores should not be considered.

Thanks for all your help on this board.

 

[pqcollectibles]

The HCA is just a screening tool. In this case both diamonds score well and should be great performers. The decision will most likely come down to clarity, and the viewer's eye.

 

[diamondsman]

I would go for # 1 ,assuming that price is the same ,they are practically the same, with number one having the better color.I also don't like the fact that the H color has surface graining,in some instances that means that there is a tinge of brown to the stone,(not to say that this one does).And assuming that you are not seeing the stones I would go with the better Color.
Oh yes make sure that they are eyeclean,Many of the si2 now days are on the border of being I1's.

good luck

 

[aljdewey]

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On 1/20/2004 1:32:18 AM Stephan wrote:





The G has more desirable angles, as said pqcollectibles, if we believe the cut adviser.
----------------

Not so. A lower score on the Cut Adviser doesn't make a stone "better". As long as a diamond rates under a 2, that's fine. Anything after that is splitting hairs.

Further, too low of a HCA score could indicate a lack of contrast in the diamond. Many feel that below a 0.6 exhibits this.

Both score well, but the crown angle on the G diamond falls outside the superideal range, and the G stone doesn't display all of it's weight where it should - on the top.

 

[aljdewey]

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On 1/20/2004 8:44:08 AM diamondsman wrote:

Many of the si2 now days are on the border of being I1's.
----------------

This statement is complete bullsh*t! These stones are AGS graded......AGS, who is NOTORIOUS for being *overly* strict on grading.

Scot, don't ever listen to stupid statements like this one. Doing so could cost you a great opportunity for an unbelievable buy. If I'd have listened to tripe like this, I would have missed out on my stone, which was a STEAL. It's an H, SI2.....and both the vendor and the independent appraiser said it was graded VERY harshly. My SI2 is cleaner than some SI1s out there!

The key to picking a good stone is TALKING to your vendor. If this vendor is a reputable PS vendor, one phone call will tell you all you need to know. Ask them to tell you about the placement of the inclusions, the color of them, and what type they are.

I'd NEVER turn my back on considering an SI2 stone, especially from AGS.

 

[diamondsman]

aljdewey wrote
This statement is complete bullsh*t!
Please try to refrain from this kind of language,on this forum.As it is not appropriate.


cut nut wrote
( About 10% of SI2's make me happy.
An sI3 grade would make sense because so many diamonds that would have been I1 a decade
ago are SI2 today.)

I tend to agree with him, There are many that are ok,but lately I have seen lucky si2's that should have been I 's.

having been in the business, this grade is so broad as oppose to other better grades, you have to be very careful.I would also stay away from it if the si2 has a black center imperfection.


good luck

 

[Mara]

It's important to note that SI3 is an EGL graded stone....an AGS graded SI2 in my opinion is nothing to shy away from as long as you do your homework first.




I have seen a few amazing SI2 stones on here and especially ALJs...considering that combined with the few I1's that we have seen on here recently that are eye-clean...I would not hesitate to consider an SI2 as an exceptionally good deal IF you can confirm with the vendor (and they have the stone in-house...not brokered where they can't see it) that it is eye-clean from ALL angles.

Depending on your vendor as well...trust comes into play. With ALs stone, Brian at WhiteFlash eyeballed it and declared it good. She trusted him. She was NOT disappointed.




I would still go with stone #2...it has much better angles...the HCA score under 2.0 still declares it excellent.

Both stones are going to be stunners most likely, but since the 2nd one is bigger...that's my vote!

 

[Stephan]

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On 1/20/2004 10:48:56 AM aljdewey wrote:

Not so. A lower score on the Cut Adviser doesn't make a stone 'better'. As long as a diamond rates under a 2, that's fine. Anything after that is splitting hairs.

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

first diamond
light return : EX
fire : EX
scintillation : EX
spread : VG TIC 1

second diamond
light return : EX
fire : VG
scintillation : VG
spread : VG TIC 1.6

I don't think that taking consideration of a difference in fire and scintillation is splitting hairs, when you go buy a diamond.
Aljdewey, are we talking about the same thing?
Or do you think that the cut adviser and the MSU-charts are something I don't dare to name ???

 

[aljdewey]

first diamond
light return : EX
fire : EX
scintillation : EX
spread : VG TIC 1

second diamond
light return : EX
fire : VG
scintillation : VG
spread : VG TIC 1.6

I don't think that taking consideration of a difference in fire and scintillation is splitting hairs, when you go buy a diamond.
Aljdewey, are we talking about the same thing?
Or do you think that the cut adviser and the MSU-charts are something I don't dare to name ???
----------------

Stephan, I don't know if we are talking about the same thing. It certainly doesn't seem so.

Yes, ON PAPER, there MAY be (and I'll come back to that) a potential difference in the scores. I highly doubt the average Joe on the street would be able to see a difference between the stones that scores VG on fire and one that scores EX on it. It's like taking one cup of water out of Lake Superior and then asking an observer if the lake looks smaller.....the differences are miniscule, and while they "technically exist", they don't make a material difference.

Second, the HCA score is helpful......but it is not GOSPEL. How were the above HCA scores derived? Was it be entering the data manually? If so, do you know that's not the most accurate way to obtain them? The HCA in its purest form takes girdle measurements into account as well, but for the sake of simplicity, Garry's model here doesn't ask for girdle info.

I found this out when I saw my stone listed on PS and it scored 1.0 EX EX EX EX.....but when I put the data in manually, it scored EX EX EX VG. I asked Garry why. He said that HCA results on PS factor in the girdle, but when I entered the figures manually, they reflect the absence of girdle info. My stone, it seems, was right on the borderline of VG/EX.

Similarly, there is no way to know if those VGs are 1/10th of a crown angle away from scoring EX.

Going even further, these two stones likely have a different look. Many people, it seems, prefer the look of the 1.6 and 1.7 stones on the HCA because they provide more contrast.

The problem with using quantitative tools is that one automatically assumes that EX MUST BE better/more desirable than VG. That's just not always so. It really depends on what elements are most important to the buyer. Some people want more fire, and to get it, they choose a stone with a table that falls below the table size in the "sweet spot" of 55/56. While the table might be "less" desirable on paper, the effect of the smaller table improve the fire, which is MORE desireable to someone who's looking for an FIC.

Numbers don't tell the whole story......only part of it.

 

[pqcollectibles]

Now, now, AL. Don't get your panties all in a bunch.

The angles seem better on one diamond presented here, and the HCA agrees! Scot should just pick one over the other based 3 Ex's/1 Vg vs 2 Ex's/2 Vg's. Let's forget both diamonds are SI2's and that one may be much cleaner than the other.

 

[aljdewey]

----------------
On 1/22/2004 8:46:18 AM pqcollectibles wrote:





Now, now, AL. Don't get your panties all in a bunch.

The angles seem better on one diamond presented here, and the HCA agrees! Scot should just pick one over the other based 3 Ex's/1 Vg vs 2 Ex's/2 Vg's.
----------------

Honestly, a few things spring to mind here.

First, I note that neither of the above stones give information on total depth, and I cannot find these exact stones on a PS cut quality search, so I'm unclear as to how the HCA scores that are shown were arrived at.

Second, Stephan, let's talk about the accuracy of those results you believe are so critical in selecting the stone. You're not taking into account the fact that the HCA assumes all stones to be of medium girdle when you enter the data manually.

I found a stone that I *think* is the second stone - it's listed on PS as 1.256 H, SI 2 - it has all the same measurements listed (table, crown/pav angles, girdle percents, fluor...everything identical). If you enter those figures into the HCA manually, you come back with 1.6 EX-VG-VG-VG....as shown by the picture below.

However, in the following post, look at the PS search result....it's the SAME stone, and it scores 1.6 EX-EX-VG-EX. Both results are the EXACT SAME STONE. By your argument, you'd be saying to reject the stone with first set of results in favor of the stone with the second set....when they are BOTH the SAME stone!

Lastly, since you put such stock in the AGA charts, Stephan, I'd draw your attention to the fact that the crown angle and the pavilion depth percentage on the first stone both fall outside the 1A parameters. The second stone is much closer to those specifications.

Bottom line....we need to keep in mind that quantitative devices have their limitations, and there is more to picking a diamond that how many EX it scores on the HCA. Further, scoring a VG on the HCA does NOT make a stone perform less beautifully than one that scores an EX.

Based on ALL the information given to date, I maintain that I'd select the second of these two stones (PROVIDING that all else with clarity, etc. was equal).

 

[aljdewey]

And here's the second result - for the SAME STONE!

 

[caratgirl]

I would choose the 1st diamond, based on the higher color and slightly better angles. I would exercise care with the SI2 grade on either one, and the additional clouds mentioned in the G color one. If the clouds are in the center under the table and are plentiful, you may observe a 'dusty' look in your diamond in certain lighting situations. As far as the second stone, I truly have no experience with graining effects, so I bow to others opinions.

 

[Mara]

SP if you can get IdealScope images for the 2 stones...it may help make the decision. If you are feeling like you are splitting hairs...the images may help.

 

[Stephan]

----------------
On 1/22/2004 10:34:18 AM aljdewey wrote:


I found a stone that I *think* is the second stone - it's listed on PS as 1.256 H, SI 2 - it has all the same measurements listed (table, crown/pav angles, girdle percents, fluor...everything identical). If you enter those figures into the HCA manually, you come back with 1.6 EX-VG-VG-VG....as shown by the picture below.

However, in the following post, look at the PS search result....it's the SAME stone, and it scores 1.6 EX-EX-VG-EX. Both results are the EXACT SAME STONE. By your argument, you'd be saying to reject the stone with first set of results in favor of the stone with the second set....when they are BOTH the SAME stone!

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

Al, you did a good homework by finding this.
Can somebody explain why the 2 results are different?

 

[aljdewey]

Stephan....thanks. If you go back to the post above, I actually already noted why this happens.




When you do a search by cut quality, the HCA is reading ACTUAL girdle information for each of the stones listed, so the results are more accurate.




However, when you enter the data manually, you aren't asked to enter girdle information....instead, the girdle is *assumed* to be a medium girdle. I got this information from Garry....who said that often people don't have girdle measurements to enter and the goal was to maintain simplicity. Further, it doesn't impact the scoring number results....only the Ex/VG thing.

 

[Stephan]

I thought that with the total depth, table %, pavilion and crown angle, the cut adviser has enough data's to calculate the girdle...

 

[aljdewey]

----------------
On 1/24/2004 4:14:49 AM Stephan wrote:





I thought that with the total depth, table %, pavilion and crown angle, the cut adviser has enough data's to calculate the girdle...

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

Not accurately, it doesn't. You're operating on the assumption that total depth minus the crown and pavilion angles leaves the girdle.....but it doesn't. I recall several discussions on the forum as to why not.

To illustrate this, my diamond measure this: 60.5% depth, crown angle 15.2%, pavilion angle 42.8%, table 56%.

The crown and pavilion percentages (42.8 and 15.2) total 58. Subtract the 58 from 60.5 and you'd "calculate" the girdle must be the remaining 2.5%, right? Wrong! The girdle on my stone is .07% to 1.4%.

Find any AGS report online and plug the numbers into what I just did...you'll find that the remainder doesn't typically equal the girdle.

 

[Stephan]

Al, because your diamond is AGS-certed...
The girdle of your diamond will be 2.5% if it is HRD-certed.