Which of 4 diamonds would you buy? Same $s, different 4Cs combos.

[Paul-Antwerp]

Re clarity - I agree re videos - and my experience in better stores in USA is the strange use of microscopes. No idea why you need a microscope for a diamond - if it is a high clarity it will have a grading report, and lower clartiy's are easy and faster to show with a loupe. Coloured gem dealers use microscopes for obvious reasons but I have never seen a dealer using a microscope unless they are specialising in Flawless etc.

Nice to see that we are on the same page, Garry.

I also see the effect of more readily available videos on the PS-interaction these last years. Ever since wholesalers started offering video and, as a result, even virtual inventory stones came with video, you notice PS-ers putting more value into the video, unconsciously devaluing the research of Cut-Quality over exaggerated Clarity-aspects in video.

Live long,

 

[OoohShiny]

Nice to see that we are on the same page, Garry.

I also see the effect of more readily available videos on the PS-interaction these last years. Ever since wholesalers started offering video and, as a result, even virtual inventory stones came with video, you notice PS-ers putting more value into the video, unconsciously devaluing the research of Cut-Quality over exaggerated Clarity-aspects in video.

Live long,

Just to check, are we only talking about Rounds in this discussion?

I am far from well-educated on all matters diamond-related, relying basically 99% on PS-sourced education and time spent looking on JA (for example) to try to educate myself and 'develop my palate', and, so far, I still don't feel experienced enough to comment on Rounds, despite being on here for quite a while now and (full disclosure) having bought a CBI diamond for my good lady.

I do, however, feel fairly confident in terms of step-cuts (hopefully that confidence not being misplaced over-confidence... please do anyone tell me if I talk nonsense!!) and I find videos to be perhaps the most useful tool in evaluating them, most specifically in evaluating their cut quality, as static ASET images and photos only really tell a part of the story.

I have even adjusted my clarity preferences somewhat after time spent reviewing videos - I am a colour- and clarity-whore with mind-clean issues (hence the F VVS I bought my good lady, lol) but I am increasingly accepting of stones with lower clarity, even SI stones, as long as the table is clean and the inclusions don't appear to affect the performance of the stone. That would appear to be contrary to the last part of the statement in bold!


I know JA videos are really no substitute for 'Real Life' viewing and assessment (and that even a 'dirty' SI stone in a video will likely look perfectly clean from 12" if the inclusions aren't black clumps), but for those of us outside the industry, we simply don't have the ability to spend time gaining experience 'hands-on' with stones unless we are lucky enough to stumble across a local jeweler who is extremely generous with their time and happy to entertain us for likely hours with no real sales potential out of it

Maybe increasing video quality is / will (continue to) be a double-edged sword, by increasing the quality and therefore attractiveness of said videos, but also potentially increasing focus on clarity - but I'm not sure it is the same for everyone. Indeed, AIUI the industry is seeing much higher demand for good SI stones than VVS stones, which would seem to indicate that people (generally and on PS) are actively seeking out and choosing these stones, either in advance of purchasing or when presented with a range of options in a store, and it seems evident that most PS-recommended retailers actively cater for this trend, with very few VS1 and above stones in inventory at any given time. If video is enabling more people to identify and purchase these eye-clean lower-clarity stones, then surely that is a good thing? And after all, the PS-recommended vendors seem unlikely to offer any stones with inclusions that would affect performance, so does it matter if people are focused on clarity if the stones (when videoed) are obviously performing well and not suffering any negative effects from inclusions?


I'm not sure I really have any actual conclusion to this post... lol, but that's a few random thoughts from me that can be ignored if nonsense

 

[Garry H (Cut Nut)]

I promised I would do an update with actual info today.
Sadly, I can not find the original scans of the stones and I have them all set into a display box now and do not want to pull it apart and scan them. So the only info I have is from the GIA certs, sadly rounded!


All are actually 1.00ct or 1.01ct and are very close to the rounded dimensions used on the video. Their differences in size on screen are slightly exaggerated.

These 4 stones at the time of purchase were of similar value except that the D I1 stone cost a little less, however it is almost an SI3 so the stone chosen was as close as possible to the cost of the other three. RapNet diamond prices at around the time of purchase:



In order clockwise top left:

GIA 2141865391 1.01ct D I1 6.25mm VG X X, 2136099567 1.01ct G SI2 6.32mm VG VG X, 2146584749 1.01ct 6.43 H SI1 X X VG, 1149274510 1.00 J VS1 6.53mm X X X. All are None Fluorescence. None of the stones has clouds or transparency issues.

Breakdown of the stones

1. The upper left D SI1 has an HCA 3.0. However if the girdle was not so thick it would be low 2’s and has FIC attributes, i.e. it has great fire and scintillation; I think a lot of people would like it. It has no ‘Looks Like’ peripheral leakage penalty but is hit hard in the spread department by the very heavy girdle.

2. The upper right stone looks a bit better in real life because unlike the camera we have 2 eyes and each is looking from a slight angle. I have noted that because the girdle variation is extreme and both the thinnest and thickest parts are outside GIA’s X or Excellent cut rules, it actually has GIA Excellent cut proportions for table %, crown and pavilion angles. It has only a very small Looks Like peripheral leakage penalty that adds to its total depth related spread penalty making it 0.08ct smaller looking.

3. This stone is on the ‘Tolkowsky line’ meaning that because it has a 0.25 degree steeper pavilion angle than Mr T’s 40.75, one multplies 0.25 x 5 = +1.25 added to the crown angle making the equivalent of 34.25 degree crown angle, ¼ a degree shallower than the ‘T’ optimum 34.5 degrees.

4. This stone is a slightly shallow 60:60 (60:59.3% depth). As in stone 3 above, if we add 1.25 degrees to the crown angle it is still a bit shallow at 33.25 degrees. The benefit is a very large spread, and infact the colour is less apparent face up because of increased brilliance (shorter average ray paths through the stone reducing the absorption of blue energy by Nitrogen (N3) the most common cause of yellow tinted diamonds). But as a result of the smaller crown area and lessor crown angle there is noticeably less fire.


Any questions?
(Clearly from the results the H SI1 close to Tolkowsky is the favoured pick.)

 

[blueMA]

Love the video Gary. I think comparison videos such as this is extremely useful.

One suggestion I could ask - if you could post such a video comparing what are considered as average super-ideals (shallower, around 34.5 crown 40.8 pav, etc) next to the diamonds of decent cut (such as H SI1) under various lighting, that would be super helpful for most newbies along with the rest of PS community.

 

[pearaffair]

Love the video Gary. I think comparison videos such as this is extremely useful.

One suggestion I could ask - if you could post such a video comparing what are considered as average super-ideals (shallower, around 34.5 crown 40.8 pav, etc) next to the diamonds of decent cut (such as H SI1) under various lighting, that would be super helpful for most newbies along with the rest of PS community.

+1

And a new thread for it so that I notice it

 

[doberman]

Both the H and the J were too warm for my liking and that's what I notice first. The H was cut well, but it looked kind of dingy to me. I liked the D color the most, my eye was drawn to it. The problem is that while I'm fine with a D SI1 stone (I have one of those) I'm not fine with an I1 clarity. I'd really have to evaluate it in person.

 

[Garry H (Cut Nut)]

Both the H and the J were too warm for my liking and that's what I notice first. The H was cut well, but it looked kind of dingy to me. I liked the D color the most, my eye was drawn to it. The problem is that while I'm fine with a D SI1 stone (I have one of those) I'm not fine with an I1 clarity. I'd really have to evaluate it in person.

I am not proposing anyone buy I1, H or J. This is a comparison of 4 similar priced diamonds. I can not make the D an SI and do any comparison without then changing carat weights.
This came out of a discussion about a new addition soon to be launched to HCA which will tell the likely APPARENT size of a diamond - not just the mm spread size, but also factoring in the leakage effect near the edge of the stone.
https://www.pricescope.com/communit...ooks-like-a-0-95ct-diamond-acceptable.243685/
Paul redirected the discussion to his hatred of the rarity / colour clarity 4C's etc and so I remebered this old video I made several years ago and started this thread.

 

[Garry H (Cut Nut)]

Love the video Gary. I think comparison videos such as this is extremely useful.

One suggestion I could ask - if you could post such a video comparing what are considered as average super-ideals (shallower, around 34.5 crown 40.8 pav, etc) next to the diamonds of decent cut (such as H SI1) under various lighting, that would be super helpful for most newbies along with the rest of PS community.

I do not know what you mean. The H SI1 is the equivalent of a 40.75 34.25. what level of hair splitting do you mean?

 

[flyingpig]

Love the video Gary. I think comparison videos such as this is extremely useful.

One suggestion I could ask - if you could post such a video comparing what are considered as average super-ideals (shallower, around 34.5 crown 40.8 pav, etc) next to the diamonds of decent cut (such as H SI1) under various lighting, that would be super helpful for most newbies along with the rest of PS community.

You may want to go to youtube and search "good old gold platinum ascendancy".
There are alot of video comparison between H&A cut diamonds and near super ideal GIA XXX/AGS 000.

 

[blueMA]

You may want to go to youtube and search "good old gold platinum ascendancy".
There are alot of video comparison between H&A cut diamonds and near super ideal GIA XXX/AGS 000.

Thanks @flyingpig - I've seen those GOG videos a while back and I must say @Rhino made some of the best diamond comparison videos on the internet, not simply comparing poor steep cut GIA 3X next to the promoted super-ideals but with some good alternate value options he also offered to his customers.

 

[blueMA]

I do not know what you mean. The H SI1 is the equivalent of a 40.75 34.25. what level of hair splitting do you mean?

Gary, the hair splitting difference you should be aware is that most PSsers here tend to prefer and recommend steeper crown angle than 34.25 for more fire. There are also some who believe diamond angles don't matter as long as they're cut to exacting super standards and they'd all look the same, while vastly superior to other ideal cuts. Perhaps you can demonstrate this is either true or false.

 

[Serg]

Love the video Gary. I think comparison videos such as this is extremely useful.

One suggestion I could ask - if you could post such a video comparing what are considered as average super-ideals (shallower, around 34.5 crown 40.8 pav, etc) next to the diamonds of decent cut (such as H SI1) under various lighting, that would be super helpful for most newbies along with the rest of PS community.

Comparison between P40.6CR35.6T57 and P40.8 CR32.7T61

Movies are in Office and Fire light

 

[gm89uk]

Hey @Serg could you post the dynamic video? That would be really useful. Thanks

 

[Serg]

Hey @Serg could you post the dynamic video? That would be really useful. Thanks

@gm89uk
Did you check link? it is link to movies. You need just push the button Play to see videos .

https://cutwise.com/compare/diamond...71|23839&format=voffice8s&formatSecond=vfire8

 

[gm89uk]

Sorry Serg didn't spot that it was a link on a quck look, thanks. The 32.7 crown is holding it's own well with fire. In real life I found the difference in fire more obvious than this.

 

[Diamond_Hawk]

This is a very important point in Paul’s observations:

“ I do not like the recent trend of stressing videos of diamonds, because it automatically takes away the attention from Cut and steers it towards Clarity in an exaggerated way.”

Agreed.

 

[Karl_K]

Sorry Serg didn't spot that it was a link on a quck look, thanks. The 32.7 crown is holding it's own well with fire. In real life I found the difference in fire more obvious than this.

Fire is lighting dependent. In lighting that is highly conductive to fire you will see a much smaller difference.
In fact a less "well cut" diamond can have the greatest fire.
Cutting a stone for max fire is different than cutting a stone to look good in a lot of lighting conditions, which is different than cutting for maximum brilliance.

 

[blueMA]

Exceptionally interesting video comparison @Serg !
Most people would dismiss the stone with larger table and lower crown, yet the video shows bigger chunks of light and performs better in the fire metrics.
This explains why some people actually hate the look of some super-ideal cut diamonds and prefer poorer cut diamonds that sometimes perform better in life according to their taste, the phenomenon discussed many times over on PS.

 

[Garry H (Cut Nut)]

@gm89uk
Did you check link? it is link to movies. You need just push the button Play to see videos .

https://cutwise.com/compare/diamond...71|23839&format=voffice8s&formatSecond=vfire8

The shorter lower girdle facets on the right side shallow stone are propbably both unsusual and contributing to the fire while reducing the brightness Sergey?

 

[Serg]

The shorter lower girdle facets on the right side shallow stone are propbably both unsusual and contributing to the fire while reducing the brightness Sergey?

Garry,

1)A shorter pavilion halves could increase fire flashes size and increase them duration . you will see slightly less number color flashes with slightly longer duration . The main difference in Fire between well cut diamonds with short and long halves in Fire type( not in Fire score).
Firstly we have to start see a difference in Fire types then discuss Fire score.
Before to start grade Shiraz wine, it is necessary to compare it with Merlo, Pinotage .
2) in the end page of same link you can find fire and brilliance scores.
The right diamond has slightly higher Fire score and slightly less Brilliance score, but Fire per area are exactly same for both diamonds. The difference in scores are very small and it is not important for my opinion. The difference in Appearance is more important than the difference in scores . The difference in Appearance could be similar as between good Shiraz and good Pinotage.
If you prefer Shiraz , please do not say that a Pinotage is not so good as Shiraz .

 

[Garry H (Cut Nut)]

Garry,

1)A shorter pavilion halves could increase fire flashes size and increase them duration . you will see slightly less number color flashes with slightly longer duration . The main difference in Fire between well cut diamonds with short and long halves in Fire type( not in Fire score).
Firstly we have to start see a difference in Fire types then discuss Fire score.
Before to start grade Shiraz wine, it is necessary to compare it with Merlo, Pinotage .
2) in the end page of same link you can find fire and brilliance scores.
The right diamond has slightly higher Fire score and slightly less Brilliance score, but Fire per area are exactly same for both diamonds. The difference in scores are very small and it is not important for my opinion. The difference in Appearance is more important than the difference in scores . The difference in Appearance could be similar as between good Shiraz and good Pinotage.
If you prefer Shiraz , please do not say that a Pinotage is not so good as Shiraz .

I agree, the differences are more in flavour than in beauty Sergey.
But I disagree about the wines. Shiraz is King

 

[Doc_1]

Garry,

I voted the D
- D color is difficult to pass factoring in the diamond has good performance, even if lower colors do better on that front.
- the inclusion is dead center blends with the natural darkness where the cult circle is, had it been off center I will reconsider.
- The spread is not noticeable unless you compare to a diamond next to it and that is not the situation when diamond is set in a ring, it will be the star.