Choosing between 2 stones

[Delta]

First time poster, here. I'm sure that you all see dozens of these kinds of posts every week...

So I finally am ready to pop the question, and have been spending the last couple weeks searching for a stone until my brain is ready to explode.

Right now, [I think] I've narrowed it down to 2 stones:

Stone 1:
Round Brilliant
Certificate: EGL (an Israel EGL cert at that)
Carat: 0.90
Color: H
Clarity: VS1
Cut: Premium
Polish/Symmetry: VG/VG
Flor: Slight Blue
Girdle: Medium Faceted
Laser inscribed girdle with report #
Displays Hearts and Arrows
FireTrace says EX/EX/EX for Brightness, Fire, and Scintillation
6.31 x 6.28 x 3.7 mm
Crown Height: 13%
Table Width: 60%
Pavillion Height: 43%
Total Depth: 58.7%
Culet: None

Stone 2
Round Brilliant
Certificate: GIA
Carat: 0.91
Color: J
Clarity: SI1
Cut: Very Good
Polish/Symmetry: EX/EX
Flor: None
Girdle: Slightly Thick
Laser inscribed girdle with report #
6.10 x 6.13 x 3.91mm
Crown Height: 16%? (can't read scan of report very well)
Table Width: 56%
Pavillion Height (can't read scan)
Total Depth: 63.9%
Culet: None

The seller (Union) is very reputable, and speaking to them, they agreed that the non-US EGL certifications are often off by one to two color grades, so the EGL stone is probably closer to a J in color, and possibly even off slightly in the clarity grading. Having said that, after taking into consideration the EGL variance, both stones seem fairly comparable including price.

I know GIA doesn't put anything in their reports regarding the Hearts and Arrows, but I've heard that displaying a strong symmetrical H&A is a pretty good indicator of cut quality. Also, I have heard varying opinons on the FireTrace performance, so I'm not sure whether to consider it or not.

So, should I just forget that I even saw the listing for the EGL stone, and go straight for the GIA certified one? Or would you trust Union to give me solid advice? I've heard nothing but good things about them.

I honestly think I'm more nervous about getting the right stone than what my answer is going to be when I actually present it to my girlfriend

 

[stone-cold11]

Use the cutadviser. https://www.pricescope.com/tools/hca

UnionDiamond should be able to get you idealscope image of the stone.

The EGL stone is on the shallow side of the cut, depth is shallow, but given the 1% step size in the numbers displayed, there can be a very large variation in the performance of the stone, probably more into the shallow side resulting in possible obstruction issues. Idealscope image will tell more.

The GIA stone is too deep, total depth is too large, you can see the implication from the diameter difference between this stone and the EGL stone, same weight but 0.2mm smaller.

You can get the proportions for input into the cut adviser, angles are more accurate, from this site. http://www2.gia.edu/reportcheck/index.cfm

 

[Delta]

Hmm, okay, I got the GIA report online and found the appropriate information to enter into the HCA page...
Depth 63.9%
Table 56%
Crown Angle 36
Pavilion angle 41.2

The GIA stone has a score of 5.4
The EGL stone, gets a 1.3, however the report only shows percentages not angles... so I'll see if they can get me an idealscope image of the stone.

Looks like I'm back to hunting, but thanks for pointing me to the page, as it may have helped me avoid a costly mistake.

 

[stone-cold11]

Good hunting.

 

[Delta]

Union Diamond was unable to give me an Ideal-Scope image of the EGL diamond in question, however they were happy to run a Sarin scan and emailed me the results, which I then plugged in to the HCA tool. Resulting score went from a 1.3 to a 1.4. (58.6% depth, 59.8% table, 33.2 degree crown, 40.4 degree pavillion, 0.6% culet).

Additionally, Union did tell me that their own gemology associates looked at the stone and said if it were GIA graded, it would probably be an SI1, J color, as opposed to the VS1, H color as graded by the EGL which is what I thought. Since the price was still about the same as an actual GIA SI1, J color stone, I was ready to pull the trigger and buy it, then run it over to a local GIA appraiser to verify the tentative grading.

However, today they found a GIA certified stone, with SI1 clarity and J color that does quite well on the HCA analysis (1.0), for about the same price of the EGL stone. That stone has a 62.6% depth, 56% table, 35 degree crown, 40.6 degree pavilion.

So, it looks like I'm getting the GIA stone, but either way it looks like they are probably pretty good selections.

 

[stone-cold11]

EGL stone will probably have obstruction issue. GIA stone looks promising from the numbers.

Also, note that GIA does not certify a stone, they only grade it. There are legal ramification in the use of the word certify.

Good luck.