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By the Numbers ... Visual Differences in MRB specs

Discussion in 'RockyTalky' started by the_mother_thing, Aug 17, 2019.

  1. the_mother_thing
    Ideal_Rock

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    by the_mother_thing » Aug 18, 2019
    @yssie I’ll have to read those links in the morning; my mind is about shot for the day. Thank you for posting them!

    Any thoughts/comments on the CA/PA combos?

    Again, at the end of the day, it’ll be my eyes and wallet that decide; I just want to get an idea of things to make sure I look at & compare aside from “oooooo sparkly!” :lol:
     
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  2. yssie
    Super_Ideal_Rock

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    by yssie » Aug 19, 2019
    Honestly? I think you are more than knowledgeable enough to not be bamboozled by any initial “oooh sparkly”. So if you’ve got mind-clean needs, which IMO is realistically what we’re debating here (and IMO completely understandable if you do, because don’t we all), then I think you’d do just fine whitelisting stones that meet those thresholds then “letting your eyes and wallet decide” :mrgreen2:
     
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  3. Garry H (Cut Nut)
    Super_Ideal_Rock
    Trade

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    by Garry H (Cut Nut) » Aug 19, 2019
    Hi tMt,
    Not sure that even if both scans were deadly accurate that any single one of those differences actually could mean anything.
    But in answer to your basic CA PA question - since the combinations are inverse, there is no difference.

    Going back to my year 2000 re-discovery of the inverse relationship (which GIA missed in it's 1998 Brilliance article and AGS did not know about) but Bruce Harding first discovered 40 years ago - I used DiamCalc to show the effect using the Gilbertson-scope ray tracing model.
    https://www.diamond-cut.com.au/03_inverse_relationship.htm
    [​IMG][​IMG]

    Figure 2. These virtual diamonds and GilbertsonScope images were generated using DiamCalc by design to have similar visual properties (DiamCalc and GilbertsonScope will be discussed later). Stone 1 has a 6.5° shallower crown and a 1.2° deeper pavilion than stone 3 corresponding to an inverse ratio2 of 5.4:1 between crown and pavilion angles. Different table sizes were used in an effort to match the size of the central table reflections. The scores in the table below are from the HCA system proposed here. The strong similarities between these three stones are evident in the complex GilbertsonScope images. The shallow crown diamond on the left has more saturated colors that indicate a higher light return.
    able. Proportions of diamonds in Figure 2
    Stone 1 (AGS 7) 2 (AGS 0) 3 (AGS 2)
    Crown 30° 34.5° 36.5°
    Pavilion 41.55° 40.75° 40.35°
    Table 53.3% 57% 60%
    HCA Score 1.2 BIC 0.7 1.1 FIC

    So if there is so little difference in appearance in diamonds with 6.5 degree crown angles, and any difference is made up by a trade off in brilliance for fire etc - then 0.3 degree is neither here nor there.

    AND, really, this kind of thing drives many trade people who visit here totally into believing we are ALL nuts!

    PS scanner accuracy on lower gridle facet length is very poor. + or minus 2% maybe.
     
  4. the_mother_thing
    Ideal_Rock

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    by the_mother_thing » Aug 19, 2019
    Thank you, Yssie. ‘Mind clean’ - for me - tends to be more of a financial criterion than it is ‘this/that spec’, as this potential purchase is totally a ‘nice to do’ opportunity for me if things work out. In reality, I know both diamonds are great performers in the grand scheme, so I’m not so much questioning that. This ‘exercise’ (asking about the nuances) - for me is as much about learning some of the finer nuances as it is making the decision and buying.

    Thank you, Garry. I spent a bit of time reading through the information on that link, including the one you posted, trying to digest it all and understand if there would be any visually-distinguishable trade-off/s between the two CA/PA combos (e.g., one slightly more/less fiery, etc.). IF I read & follow you/others correctly, there are not. I’m really looking forward to seeing both in person so I can confirm with my eyes what I’m learning here. :dance:
     
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  5. whaleshead
    Rough_Rock

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    by whaleshead » Aug 19, 2019
    I understand that super ideals are the cream of the crop, but would someone really be able to tell the difference between these two stones, or in this case would going with the super ideal be more of a "mind clean" thing?
     
  6. the_mother_thing
    Ideal_Rock

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    by the_mother_thing » Aug 19, 2019
    I think that may depend on how some people define ‘mind-clean’. Also, I think some people just like knowing they have ‘the best’ even if they can’t truly see it; others perhaps have eagle eyes enabling them to see things others may not so if those ‘things’ bother them, then they may prefer to have the closest thing to perfection they can afford. Then there are people who never knew what they were missing (e.g., great cut) until they discovered it, then they couldn’t unsee the ‘negatives’ they now viewed in their diamond/s, so wanted better. It probably just depends on the buyer.
     
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  7. whaleshead
    Rough_Rock

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    by whaleshead » Aug 19, 2019
    the_mother_thing, are you planning on ordering both diamonds you referenced to compare them? I'll be interested to hear what your thoughts are.
     
  8. the_mother_thing
    Ideal_Rock

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    by the_mother_thing » Aug 31, 2019
    I am comparing them this weekend. One set of specs I posted actually belong to my current diamond. I was curious - in advance - what folks might expect to see different between the two based on the specs alone. And it seems those who said it’d be hard to discern the difference are right. To my eyes/in person, the comp/loose diamond looks like it could be my current diamond’s identical ‘big sister’.

    Below are a couple videos, as I’m curious what others see/think. Obviously, the comp diamond is in the temp ring holder beside my current diamond, which is set. Consequently, the comp sits up higher and appears a little brighter in videos; however, in person they appear equally bright. Thoughts?




     
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  9. Wewechew
    Brilliant_Rock

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    by Wewechew » Aug 31, 2019
    I feel like yours has more contrast where as the other one is brighter? But it could be camera angles and the difference in the two stones’ “settings”.

    I was wondering if this was for your five stone ring, did not expect this! Are you upgrading?

    ETA- sorry, reread your post and saw you already addressed that you see the difference on camera cut not in person.
     
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  10. the_mother_thing
    Ideal_Rock

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    by the_mother_thing » Aug 31, 2019
    @Wewechew I don’t think I’m going to do the 5-stone; if I’m real with myself, it’d just be too much ‘bling’ for me. I know, I know ... no such thing. :lol:

    I’ll probably be going with a three-stone, if anything. So yes, this is a potential upgrade from my current diamond.
     
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  11. Wewechew
    Brilliant_Rock

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    by Wewechew » Aug 31, 2019
    @the_mother_thing I’m one of the few PRers that agrees with you- I could do a three stone, but not a five. I also think my main stone size will top out around 1.5ct, *maybe* 1.75ct.

    What are the rest of the stats on this one?
     
  12. the_mother_thing
    Ideal_Rock

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    by the_mother_thing » Aug 31, 2019
    @Wewechew I’ll definitely share the rest of the specs, but want to hold off for right now as I’m hoping to just see what observations are shared based on what is seen. ;)2
     
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  13. Lykame
    Brilliant_Rock

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    by Lykame » Sep 2, 2019
    Oooh your diamond and that larger diamond are awesome; I agree the larger one looks like a bigger sister.

    I saw two CBIs in person next to each other and I could definitely see the difference in them light performance wise.

    https://www.hpdiamonds.com/en-us/diamonddetail/HPD9893
    That was a 1.875, J, SI1.
    7.94 x 7.96 x 4.88mm
    Table 55.8
    Crown 34.4
    Pavilion 40.7
    LGFs 77

    The second was:
    https://www.hpdiamonds.com/en-us/diamonddetail/HPD10351
    That was a 1.853, J, VS1
    7.87 x 7.91 x 4.85mm
    Table 56.3
    Crown 34.4
    Pavilion 40.7
    LGFs 77

    As you can see, they were SO CLOSE to each other. But next to each other I could A, annoyingly see the size difference (ridiculous I know) and B, they had different personalities with their light performance. I was somewhat flabberghasted by this, but they did not look the same. I preferred the 1.87 light performance (likely because of the smaller table) but couldn't tolerate the fact it was SI1 (mind clean issues) so I ended up getting neither. Based on my reading here and that experience I ended up choosing a stone with a tiny table and 76 LGFs. Love it. I think it's ruined me for upgrades though as I think there's now only a very few angle/percentage combinations I would be keen on and that would include having only 75 or 76 LGFs.

    Be careful, it's a slippery slope! :lol:
     
  14. MissGotRocks
    Super_Ideal_Rock

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    by MissGotRocks » Sep 2, 2019
    I really can't see any appreciable difference in performance between the two stones.

    It does look like the larger stone is a different color than your stone and of course you can see the size difference.
     
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  15. Wewechew
    Brilliant_Rock

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    by Wewechew » Sep 2, 2019
    Yes!!! It’s kind of annoying. And very limiting.
     
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  16. the_mother_thing
    Ideal_Rock

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    by the_mother_thing » Sep 2, 2019
    Thank you @Lykame & @MissGotRocks for chiming in with your experiences & observations. This exercise has been very educational for me. I’m now convinced that unless one has really scrutinized a lot of ideal-cut diamonds and combinations of angles with some level of regularity, they’re not likely to detect such minute differences in performance. I’m really struggling to see differences in person/to the naked eye between these two diamonds, but I do believe I can tell the arrows in my diamond (76 LGF) appear thicker than those in the loose diamond (77 LGF) in normal viewing. But the loose diamond being bigger kind of makes it all equate overall, if that makes sense.

    As far as color is concerned, both are the same diamond color per their respective lab reports (both AGS). As I mentioned in my earlier post, the camera makes the larger diamond appear a smidge brighter in the earlier posted videos because it’s in a temp ring holder and sitting up higher than my diamond. In person, focusing on only the diamonds (and ignoring the settings), I cannot detect any difference in actual body color if I don’t take into account the size difference. I believe - since there is more surface for light to enter the larger diamond, it would stand to reason the loose diamond would appear ‘brighter’ to the eye but only because it’s bigger.

    A few pics in various light settings with the loose diamond sitting in an empty platinum setting so they’d be on the same level.
    73CCDB0F-1039-42F4-AD21-0E51938089B2.jpeg

    00C20BD0-BBDD-4DB3-B909-9B1BA970FEB2.jpeg

    And a couple more videos:




     
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  17. the_mother_thing
    Ideal_Rock

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  18. Wewechew
    Brilliant_Rock

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    by Wewechew » Sep 2, 2019
    I’ve been waiting for the update! It’s been so nice to see someone else being as meticulous about a possible upgrade :lol:

    Have you taken them around to different lighting conditions? That was the most apparent way for me to be able to see differences in proportions.
     
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  19. the_mother_thing
    Ideal_Rock

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    by the_mother_thing » Sep 2, 2019
    I am definitely scrutinizing both diamonds because (like most PSers), this isn’t ‘just a ring on my finger’. I care about my rings and performance, I observe them where ever I go, in different light settings, etc. so I want to make sure that any new diamond is going to be as good or better than what I have now. This ‘test’ has proven that ‘better’ is likely going to be negligible at best except in size (since I’m not going up/down in diamond color). I have taken them around to just about every lighting condition I can find in & around my home (which has mostly beige walls, FYI) ... natural light, outdoors, indoors, sparkly lights, dim lighting, fluorescent lighting, etc. ... so much that my freaking wrist is KILLING me from holding it at various angles so I can see both this way, that way, etc., and I know hubs is tired of seeing me walk around the house like that the last two days. :lol:

    So far, the only difference I can notice is the LGFs/arrow thickness, but it’s negligible and hard to really gauge because of the overall diamond size difference. Otherwise, they really do seem to perform/appear the same (to my eyes), and that’s not a bad thing because I love my current diamond and how it performs. But I have reasons for considering this particular new diamond as a potential upgrade beyond just size.
     
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  20. Wewechew
    Brilliant_Rock

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  21. Lykame
    Brilliant_Rock

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    by Lykame » Sep 2, 2019
    I fully fully agree with you - I think that if I hadn't seen the two diamonds right next to each other, I would have had NO CLUE that there were differences between them, and I would have been delighted by both of them. If I had separated them out and been presented with both individually, I'm not sure I would have been able to identify which was which. It was only possible because they were next to each other. I think although there may be some personality changes between the interplay of the numbers, it's going to be very subtle.

    Also, your signature bemoans the difficulty of taking photos of diamonds (certainly something I relate to immensely) but your pictures are glorious. How do you do it? :cry2:
     
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  22. the_mother_thing
    Ideal_Rock

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    by the_mother_thing » Sep 2, 2019
    Agreed - if I saw both these diamonds separately, I’d love both equally and would have difficulty choosing. As it is, I need to make a decision, and believe I know where that decision has landed.

    For pics/videos, I use both my iPad Pro & iPhone XR, making sure I clean the camera lens on both, and try - where possible - to have the iPad/iPhone and the item stabilized. Also, for close-ups of diamonds/stones (like the one in my avatar), I attach my loupe to the iPad to zoom in on the details. But I don’t use/add any sort of filtering or make any edits in Photoshop/the like.
     
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  23. MissGotRocks
    Super_Ideal_Rock

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    by MissGotRocks » Sep 2, 2019
    While the numbers on those two particular stones are not that far off from one another, it is interesting to note the consistency in their performance. Makes you wonder how important the t/c/p numbers really are as long as they are complimentary and the diamond passes the analysis of light performance. Very interesting!
     
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  24. Wewechew
    Brilliant_Rock

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    by Wewechew » Sep 2, 2019
    Makes you kind of wonder how crazy we really all are :whistle:
     
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  25. MissGotRocks
    Super_Ideal_Rock

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    by MissGotRocks » Sep 2, 2019
    It really does - kind of scary! How many times have we read as long as you are choosing an ACA you don't have to worry? Same thing with CBIs. They are meticulously cut for light performance so maybe we should all just be choosing carat, color and clarity and the rest be damned! What would we do with our time then? LOL!
     
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  26. Wewechew
    Brilliant_Rock

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    by Wewechew » Sep 2, 2019
    @the_mother_thing when trying to decide to keep it, have you thought about how you would set the larger stone?
     
  27. Wewechew
    Brilliant_Rock

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    by Wewechew » Sep 2, 2019
    I could be so productive in all areas of my life :lol-2:
     
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  28. whaleshead
    Rough_Rock

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    by whaleshead » Sep 2, 2019
    the_mother_thing, would you be willing to share what your reasons are for considering this new stone? And possibly where you got the stone from? The larger one is the one that is not a super ideal, correct?
     
  29. the_mother_thing
    Ideal_Rock

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    by the_mother_thing » Sep 2, 2019
    I think this is somewhat true based on this/my experience. There are some relatively minor differences that - being aware of diamonds & cut more-so than perhaps the ‘average consumer’ - I can detect in my environment. And I can only assume they are based on how each particular diamond’s angles are cut and complement each other coupled with what one’s eyes prefer (if they have seen enough to gauge such) ... and in conjunction with whatever other ‘priorities’ or factors a buyer has in making such a decision. For the ‘average’ consumer who hasn’t honed their eye, knowledge and preferences, I think they could easily be presented with either diamond, find both visually pleasing, excellent performing, and be thrilled with either choice that best fit their budget/criteria, and not really discern any major differences.

    For me considering this upgrade, it is dependent on not only performance and what my eye prefers, but also my critical ‘mind clean’ factor - the financial/cost factor. The differences really need to be significant enough for me to justify the cost for what I’m trading up to; in this particular situation, I’m just not sure that they do because of the limited difference I see for what it will cost to upgrade to this particular diamond, given it’s not with the same vendor as my current diamond.

    And before I share the specs of the potential upgrade diamond, I want to be crystal clear because I’m sensitive to both vendors involved as well as owners of diamonds from both: none of what I shared here is to suggest (nor should anyone infer) that the potential upgrade diamond doesn’t perform well - it absolutely, positively does perform amazingly. Someone else may very well see something different and choose differently. For me, it just means that my current diamond (a WF expert selection) is such an outstanding performer that it’s hard to give it up and spend more money to go bigger than I would if I stayed with the same vendor and received full cost trade-up value. The comp diamond is this CBI, which unfortunately would just result in too much loss of what I originally spent to feel comfortable trading in my diamond where the only significant difference I can see is an additional .37 ct/.6mm spread. I hope that makes sense, and that no one infers I’m suggesting one is better than the other, especially the vendors ... both of whom are/have been beyond incredible to deal with. :wavey:
     
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  30. Wewechew
    Brilliant_Rock

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    by Wewechew » Sep 2, 2019
    @the_mother_thing You know I love my CBIs, but given your current diamond, I 100% would have made the same decision you are. Your WF ES has the 76 LFG that I love, AND the fluorescence. And that’s not even factoring in the financial side of it.
     
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