Some help reading idealscope images

[DiamondDude82]

I'm a long time lurker who is popping the question in the coming weeks. I'd like to thank Garry for making the HCA tool, the guys from GOG for writing so many articles that made me understand how painting and digging could ruin a stone with a great HCA score, JA for creating an amazing website for viewing their diamonds, and finally everyone here for being so helpful to newbies like myself.

My girlfriend is color sensitive so I kept the diamonds I looked at either G or above. Size isn't everything but I looked for 1.5ct round eye clean SI1s. Below are the two diamonds that I was able to find from JA that I feel met these requirements. The issue is I don't have enough experience reading idealscope images to trust making the decision. I'm hoping a few of you wouldn't mind lending your expertise to help me out.

Diamond 1: http://www.jamesallen.com/loose-dia...-g-color-si1-clarity-excellent-cut-sku-201625
1.6ct, G, SI1
HCA: 2.7
Table: 57%
Depth: 62.5%
Crown angle: 35.5
Pavilion angle: 40.8


Diamond 2: http://www.jamesallen.com/loose-dia...-g-color-si1-clarity-excellent-cut-sku-204012
1.54ct, G, SI1
HCA: 2
Table: 59%
Depth: 60.7%
Crown angle: 35
Pavilion angle: 40.8


Notes from the Gemologist:
-Recommends Diamond 1, though Diamond 2 is a close second.
-Both are eye clean

My concerns:
-Diamond 2 is almost a thousand dollars less. Don't get me wrong, if Diamond 1 is the clear winner then I don't have an issue spending the money, but I'm just noting it.
-I'm surprised that he said that Diamond1 was better as to me it looks like it has a bit of leakage under the table (what some people call the ring of death), and the angles aren't as close to ideal as Diamond2.
-Lastly, I am trying to stretch my budget a bit to break the 1.5ct barrier, so please tell me what you think of these stones overall and if I should be looking at something of higher caliber and a lower carat weight.

 

[teobdl]

If these are your final choices, I would choose Diamond 1 for three reasons:
1. The lower girdle facet length of diamond 2 is super long (85%!), which results in very skinny pavilion facets. You can see how skinny these facets are by seeing how skinny the arrows of diamond 2 are compared to diamond 1.
The pavilion facets influence character of light performance more than any other aspect of diamond cut. Though the length of LGF’s has been debated many times here in the past, many posters from the business say consumers prefer LGF’s of 80% and below, and anything above 82% (I think) is most likely detrimental to performance. I’m just parroting what I’ve read, so others can feel free to disagree here. If you look at branded super-ideal cuts from WhiteFlash, Brian Gavin and Crafted by Infinity (all well known here for their precision, super-ideal cuts), nothing is above 80%.
2. Diamond 2’s table is bigger than most prefer.
3. The gemologist says Diamond 1 is better.

That said, the crown angle of Diamond 1 is a little higher than some here prefer... it will likely be more fiery and slightly less bright when compared to diamonds with everything the same, but with a lower crown angle . Also, higher crown angles, it’s been said, will be impacted by dirt/grease more than shallow crowns, so just be sure to keep it clean. Nothing kills light performance more than a dirty diamond!

 

[bunnycat]

I'd go with the gemologist rec in this case. My personal preference is not to have those teeny tiny thin arrows. I like them chunky.

Also, you might see if you can keep that first on on hold just a bit longer and let PSers come up with a third choice for you. You get 3 IS images and gemologist reviews so you might as well find a final contender. You can post your budget and other preferences and see what people find.

 

[DiamondDude82]

Hmm, I'm getting the impression that the feeling is there is better out there. I appreciate the honesty. I've already used another idealscope from JA so I'm at my limit. The first one ended up being one of those rare cases where the HCA was great, but it ended up being a dud. That's why I started doing more research.

My budget is $15k, no more.

I found two nice ones on BN, but I'd have to buy them both to look at them under my own idealscope. The Gemologist at BN says they are both eye clean. I'm willing to do that so if you think either one of these have a better potential than Diamond1 above let me know.

Diamond 3: http://www.bluenile.com/round-diamond-1-carat-ideal-cut-f-color-si1-clarity_LD03463142
1.59ct, F, SI1
HCA: 0.6
Table: 56%
Depth: 61.6%
Crown angle: 34
Pavilion angle: 40.6
Lower girdle facet length: 80%


Diamond 4: http://www.bluenile.com/round-diamond-1-carat-ideal-cut-f-color-si1-clarity_LD03233727
1.51ct, F, SI1
HCA: 0.9
Table: 58%
Depth: 61.2%
Crown angle: 34.5
Pavilion angle: 40.6
Lower girdle facet length: 80%

 

[JulieN]

The first one is actually really great, no issues. #4 looks good but smaller than #1.

 

[DiamondDude82]

I just put this one on hold at JA. They said if release the other two that they will make an exception and do a 4th idealscope. Is this one worth it? Thanks everyone for the help on this.

Diamond 5: http://www.jamesallen.com/loose-diamonds/round-cut/1.50-carat-g-color-si1-clarity-excellent-cut-sku-164133
1.50ct, G, SI1
HCA: 0.7
Table: 57%
Depth: 60.4%
Crown angle: 33
Pavilion angle: 41
Lower girdle facet length: 80%

 

[JulieN]

that should be good too, but it has a VTN girdle.. #1 hews more closely to the PS ideal.

 

[DiamondDude82]

The first one is actually really great, no issues. #4 looks good but smaller than #1.

Thanks for the input! Just curious, why does #4 in your opinion have more potential than #3?

 

[JulieN]

Looks tilted (probably the photography, not the stone's fault), black speck in the middle (that I can't find on GIA report.)

 

[DiamondDude82]

Looks tilted (probably the photography, not the stone's fault), black speck in the middle (that I can't find on GIA report.)

Very true. I saw that as well, but noticed that crown on #3 was returning a bit more light (I know not very scientific), but that could just be due to it being a bit off center in the picture.

Are there any follow up questions I could ask the Gemologists at BN about #3 and #4 to try to differentiate them a bit more, or are they likely as similar as it seems?

 

[JulieN]

#4 is the "safer" choice, #3 a little bit shallow 34/40.6 combo.

 

[DiamondDude82]

#4 is the "safer" choice, #3 a little bit shallow 34/40.6 combo.

So, that 0.5% difference on the crown angle with the same pavilion angle makes that much of a difference? I'm a bit concerned about purchasing from BN since I'd have to trust myself with an idealscope. Would you still purchase #1 over #4?

Do any of these really stand out or is my budget just too low to get a diamond that is up to PS standards with this carat weight and color rank?

 

[JulieN]

You don't need an IS for #4, those angles are unlikely to leak and the picture looks good.

Price for #1 and #4?

15K is fine for a 1.5 G SI1.

 

[DiamondDude82]

You don't need an IS for #4, those angles are unlikely to leak and the picture looks good.

Price for #1 and #4?

15K is fine for a 1.5 G SI1.

#1: 14.5k (G)
#4: 14.7k (F) (but I might be able to get BN to price match the JA stone)

In the end what is important to me (as most PSers) is that it performs well. I'm willing to buy both #1 and #4 so that I can see them both in person and then return one, but if one of these is really likely to outperform the other I'd prefer not to take the risk and just purchase one.

 

[JulieN]

If it would bother you to return one, the cheaper and bigger one is usually at the top of the list.

 

[DiamondDude82]

If it would bother you to return one, the cheaper and bigger one is usually at the top of the list.

That's pretty fair

Oh and if you are curious here is the other idealscope that I had. As you can see from the real image and the idealscope something seems to be off even though the proportions look good, right?

http://www.jamesallen.com/loose-diamonds/round-cut/1.50-carat-f-color-si1-clarity-excellent-cut-sku-224472
1.5ct, F, SI1
HCA: 1.1
Table: 57%
Depth: 60.9%
Crown angle: 33.5
Pavilion angle: 41
Lower girdle facet length: 80%

 

[JulieN]

There's some girdle treatment going on to save weight. GIA still gives it an EX, though, and it is a nice icy white.

This is why I shy away from diamonds that fall exactly on 1, 1.5, 2 cts. Lots of them are good. Many more are not good.

 

[DiamondDude82]

There's some girdle treatment going on to save weight. GIA still gives it an EX, though, and it is a nice icy white.

This is why I shy away from diamonds that fall exactly on 1, 1.5, 2 cts. Lots of them are good. Many more are not good.

I'd been watching this diamond for a while and no one had bought it. I grew more suspicious of it as I became more educated, and honestly if it weren't for PS I would have bought it over a week ago. I really dodged a bullet with that one and I owe it to the people of this forum.