Down to two stones - What do you think?

[Nick payne]

Considering two great stones I have seen in person. Both have excellent brilliance and fire, and both are colorless enough, and both are probably an acceptable option.

I have this 2.05 I SI1 stone in my possession: <https://www.goodoldgold.com/diamond...t_round-EX-GIA--SI1-diamond-stock-14114-cert->.

I am considering this 2.14 I SI2 stone: <https://www.gia.edu/report-check?reportno=2185976443>.

The angles are very similar: they have the same pavilion. The 2.05 has a 35.5 crown and a 55.6 table while the 2.14 has a 36 crown an a 58 table. I would love to know what the differences in angles should cause me to see visually as to me it looks like the one has thinner arrows than the other.

Here are the key differences:

2.14 I SI2
-It is a little whiter/a little less colored; although, both are I color leaning to H on colorometer.
-The arrows are a little thicker looking
-It does have a white inclusion that can be seen with the naked eye, but not in dim or bright lighting and I typically have to locate it with a loop to see it with the naked eye. It is not a deal breaker.

2.05 I SI1
-Thin arrows, but still distinctly visible: of the two this stone has better hearts in the H&A viewer
-Totally eye clean
-Noticeably more dispersion than the other but similar brilliance
-I don't think the size difference is that descernable

I would love to hear thoughts, concerns, or opinions!

I will attach some video.

 

[Nick payne]

The video is below. The lighting was florescent from above but we were near a large window on a cloudy morning.

 

[yssie]

The pavilion mains create the arrow shafts that you’re seeing face-up. Shaft thickness is determined by length of lower girdle facets (shorter LGF = thicker pavilion mains), shaft length is determined by table size (larger table/shorter upper girdle facets).
See a much more complete explanation from JohnQuixote (John Pollard, who was with Whiteflash and is now with Crafted by Infinity) on Pg1:
https://www.pricescope.com/community/threads/diamond-performance.47957/

It seems like based on what you do see, ignoring for the moment your question about what you should see, that you prefer the 2.05? If so... your choice should be clear!!

To answer your question in a bit more detail...

1. Generically... table, crown, and pavilion angles should be complementary such that total internal reflection off the pavilion facets (of light inbound through table/crown) is possible through a maximal range of inbound angles. This is a red flag sort of question - “are there flags in the numbers or not” - and there aren’t with either stone, so moving on.
2. Given the same crown angle, a smaller table means crown facets are larger. Larger facets mean more space and angular difference between adjacent dispersions, which means less chance of interference, which ultimately means higher odds of seeing coloured output. Larger facets also mean larger virtual facets which support higher-energy secondary and tertiary internal reflections and eventual refraction out of the stone. This is all massively oversimplified.
3. Given the same table size, a higher crown means crown facets are larger and steeper. The theory of (2) holds... with the caveat that at some point (which MRBs rarely reach, but I’ve seen some questionable cushions...) the difference in angle between crown and table becomes large enough to demand an exaggerated difference in pavilion facet angles (since we’re talking about RBs here that’s mains/LGF) for hope of some of that pavilion meeting critical angle. Meaning - I would not combine large table, excessively high crown, and longer LGF. What’s “excessive”, “large”, “long”? Well, this will vary by stone (minor facets, precision of cut).

But here’s the important thing: None of this matters because you’re looking at both stones and your eyes have a clear preference. All the math and biology driving optics and perception - and there’s so much more than the kibble I posted just now - won’t tell you what you should prefer, that’s for your eyes to judge. I posted more info above because you asked for more info, but I urge you not to get caught up in “should”.

 

[diamondseeker2006]

It's hard to tell much in the videos in jewelry store lighting. I generally am an SI1 and up fan. Do you have an ASET image of the 2.14?

 

[Nick payne]

I do not have an ASET for the 2.14. Under an H&A viewer the arrows were apparent and I was able to distinguish hearts by tilting the viewer a bit.

 

[ringo865]

Which is which in the video on your pinky?

 

[diamondseeker2006]

I just saw your other thread. I wouldn't consider the 2.14 because of the inclusions and the numbers are slightly out of the most desirable range (meaning I wouldn't consider it without an ASET image because it could have more leakage than the other stone). If these are the only two stones you'll consider, I'd go with the 2.05.

 

[Nick payne]

Ringo865, It is the one closest to my hand, the bottom one.

 

[Nick payne]

After thinking it over and reading the comments, I think I am going to stick with the GOG stone.

Reasoning being even though the other stone is a little less colored and maybe a little whiter facing up, it has an ever so slightly visible inclusion and GOG has a great upgrade policy while the local dealer does not do upgrades.

Thanks to those who commented on this or my other thread.

 

[ringo865]

The on on the bottom of your pinky was the 2.05 I SI1 from GOG? That your keeping? That is the one my eye kept going to. Granted it's a video I watched on my phone. But it actually looks bigger and brighter, and less body color than the other stone. So. Paper, as they say "looks good on paper"... But the eyes see what they see. Please come back and show off a little when you get it?

 

[cflutist]

I just saw your other thread. I wouldn't consider the 2.14 because of the inclusions and the numbers are slightly out of the most desirable range (meaning I wouldn't consider it without an ASET image because it could have more leakage than the other stone). If these are the only two stones you'll consider, I'd go with the 2.05.

I am with @diamondseeker2006 . An eye visible inclusion would drive me bonkers. Also the 2.05 has more dispersion and better H&A. Size isn't everything. What is GOG's trade-in policy in case you want to go bigger and better in the future?