Help! Choosing between two round brilliants

[firsttimer1234]

Both are GIA graded and similarly priced enough where both are in budget. Buying from local jewelers but these are in different stores, so it is hard to compare side by side, but I like both. Would love some input/thoughts on the below specs. Thanks!!

Option 1:
Measurements 8.52 - 8.57 x 5.26 mm
Carat Weight 2.31 carat
Color Grade H
Clarity Grade VS2
Cut/Polish/Symmetry Excellent
Flourescence None

Depth 61.6%
Table 56%
Crown Angle 34.5°
Crown Height 15.0%
Pavilion Angle 41.4°
Pavilion Depth 44.0%
Star Length 50%
Lower Half 80%
Girdle Thin to Medium, Faceted, 4.0%
Culet None

Option 2:
Measurements 8.62 - 8.64 x 5.06 mm
Carat Weight 2.26 carat
Color Grade H
Clarity Grade SI1
Cut/Polish/Symmetry Excellent
Flourescence None

Depth 58.6%
Table 61%
Crown Angle 32.5°
Crown Height 12.5%
Pavilion Angle 41.0°
Pavilion Depth 43.5%
Star Length 55%
Lower Half 80%
Girdle Thin to Medium, Faceted, 2.5%
Culet None

 

[firsttimer1234]

Wink - thanks for the response! If you don't mind - can you help me a bit with terminology? What does AGS predictive light performance mean? Is light dispersion what people generally call "fire"? How does that differ from brilliance?

Would you never settle from something less than an AGS 0? If not, what info can I look to while in a store to determine is something would come out to an AGS 0?

Lastly, what are the typical effects of having a shallow crown and big table?

Again - thank you so much! As I am sure you all hear on here all the time, this is a pretty daunting process so any help is very appreciated.

 

[WinkHPD]

Wink - thanks for the response! If you don't mind - can you help me a bit with terminology? What does AGS predictive light performance mean? Is light dispersion what people generally call "fire"? How does that differ from brilliance?

Would you never settle from something less than an AGS 0? If not, what info can I look to while in a store to determine is something would come out to an AGS 0?

Lastly, what are the typical effects of having a shallow crown and big table?

Again - thank you so much! As I am sure you all hear on here all the time, this is a pretty daunting process so any help is very appreciated.

Yes, and I apologize for not thinking that you may not be versed in my every day thought processes. It is a danger that we sometimes ignore at our own peril.

The American Gem Society Laboratory issues AGSL Diamond Grading reports. These are most often referred to as AGS Reports rather than the AGSL Reports that would be technically correct.

Their top cut grade is AGS 0 light performance. This is determined by running a computer simulation on the actual measurements of the diamond that runs 40,000 rays of light through the diamond to determine how the light is reacting within that diamond. The measurements are made with VERY expensive machines that the average jeweler can not afford in his wildest dreams.

John Pollard has published on here somewhere a poster that shows diamonds with as low as AGS 5 or 6 Light Performance grades still getting a GIA Excellent cut grade. For this reason, an AGS 0 Light Performance grade diamond sells at a premium to a GIA Excellent cut diamond.

Many will tell you then, that any AGS 0 cut grade diamond is good enough, and for many, it is. However, like any grading category, there are those at the top of the grade, and those hanging on with both hands to just barely get their chin over the bar. Thus, as with any diamond with any report, you MUST SEE the diamond to know if it is the one for you. Cutters have a propensity to cut to the bottom of the grade to get away with shortcuts and claim they are at the top, when other cutters cut only for perfection and beauty, but must charge a premium. (Sort of like, do you want a top of the line Seiko, or do you prefer a Patek Philippe?)

When I speak about an AGS predictive light performance cut grade, it is the result of entering that diamond into an excellent software program called DiamCalc that gives me a strong prediction of how the diamond will perform when the light ray tracing is done at AGS.

Since we do not have either the machines to measure to the necessary perfection that AGSL would measure them, nor the sophisticated ray tracing technology, we can issue only an estimate of what the diamond's light performance grade would be, and of course, the polish and symmetry grades must also be issued directly from AGSL to have any validity. Thus I try to be careful to say that this has an AGS predictive light performance grade, just in case I am wrong.

Yes, you are correct that dispersion is what most call fire. It is achieved when a dispersed ray of light (think bent and remember playing with prisms as a child and throwing rainbows on your wall) is wider when it reaches the pupil of the eye than the pupil. If not and the entire ray of light enters the pupil, then it will have all of the colors within it and be perceived as white light, or sparkle.

The reason that I do not like shallow crowns with large tables is that they rarely bend the light sufficiently to allow the human eye to perceive them as colored light. So such a diamond will tend to have lots of sparkle, but little, if any fire.

I specialize in diamonds that are cut to the very tip of the pyramid, in the very top of the AGS 0 cut grade, so no, personally, I would never settle for less for my own personal use. I recognize though, that many are perfectly happy with that fine Seiko. It is not my place, or even my desire to say what you may want and should have. It is my desire though, to share lots and lots of information with any who ask so that you may make a more informed decision, based on your needs and also on your budget.

While looking in stores that do not carry AGS reports, you can ask them if they will bring one or more in for you, some will, some wont. You can also learn to use such devices as the ASET and the Ideal-Scope and buy hand held versions of them to use at your local stores. This will fascinate some sales associates and threaten others, so you may be welcome in some places and thrown out of others. You may expect high quality independents to be more supportive of this than your local (Insert Name Here) chain store.

You can get both The Ideal-Scope and the ASET from David Atlas, who goes my OldMiner here.

I did not mean to write you a telephone book, but it is nice after a week of ten to fourteen hour days to have the time to fully and properly express myself. I hope your weekend is going as wonderfully as mine.

Wink

 

[16ocean]

Hi firsttimer1234-
Out of the two round brilliants you posted I like option number 2 better,

Option number 1 has too high of a pavilion angle and when you run it through the HCA
4.6 - Good - Only if price is your main criterion

I choose to ELIMINATE diamonds that scores over 2.0 on the HCA and would NOT buy option #1


option number 2
does score under a two how ever I tend to like smaller tables and cut a bit deeper.
1.6 - Excellent

Do you want to go with a local jeweler or are you open to buy online?

 

[ponyrider]

To help further my own education, I see that choosing the best clarity is NOT always the best option?

 

[16ocean]

To help further my own education, I see that choosing the best clarity is NOT always the best option?

I am not an expert but what I am learning is for me it is a balance. I think of all -five- elements
cut
clarity
color
carat
&
cost

Everyone is going to have different priories of what is most important for them. Just bz a diamond has a higher clarity doesn't necessarily make it the better choice.

To me clarity is abt eye clean.
I don't walk around w/ a loop so if it is eye clean and clouds don't diminish the brilliance it SI1 works for me bz then I can go higher in other areas.

It's abt finding your preference.