How important is HCA score? Why such differences in $? Help!

[Buschman98]

I'm trying to decide on a diamond in approximately the 1.5 carat size.

I definitely stress the cut and life of the diamond far above clarity and I do want H or better color (preferably G).

I've been focusing on H&A diamonds because I like the contrast they give in the lights/darks areas in the table.

Now, I'm trying to wrap my head around some prices I see and trying to figure out what I'm dealing with and what's the best, most brilliant (yet "colorless") stone I can find that's eye-clean.

Some stones I'm considering (All H&A) are:
http://www.goodoldgold.com/diamond/8892/
1.5ct G SI1, AGS0 but a 2.8 HCA for $15,600
61.4 depth
55.4 table
40.8 pavilion angle
34.3 crown angle
My concern with this one is the 2.8 HCA and the actual diamond pic doesn't show good contrast in the table like the rest of the stones in this post. What should I expect in relative performance for a 2.8 HCA vs something below 1.5? Also, despite the AGS0, it only gets a very good on the GIA grading included with the stone. Also, what's up with the DiamXray and no IdealScope? There's no way this thing could have zero leakage (no white spots) like the DiamXray seems to indicate, right? Lastly, the feather inclusion is clearly visible in the photo supplied, do you think that'd be eye clean? Sarah from GOG says it's not.


http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2671391.htm
1.518 G SI1, AGS0 1.4 HCA for $16,800
61.9 depth
55.0 table
40.6 pavilion angle
35.6 crown angle
My concern here is despite the AGS0, H&A, its listed as only "expert selection" from whiteflash rather than a cut above. Why? Also, do I see an inclusion right in the center of the table? I think that may be eye-visible and cause me to eliminate it.

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2709001.htm
1.52 H, VS2 AGS0 1.1 HCA $18,479
61.2% depth
57% table
40.7 pavilion angle
34.7 crown angle
My concern here is the picture of the diamond shows a lack of detail. Things seem washed out in general and around the perimeter I can't really see contrast in the facets compared to other stones. For instance, check out the difference in this stone's busyness compared to the next one.
http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2666574.htm
There's so much more going on in this one, but the inclusions in the table may be a bit much for me.

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2708998.htm
1.51 H VS2 AGS0 1.6 HCA $18,345
61.8% depth
57.0% table
40.8 pavilion angle
34.9 crown angle
No real comments. It looks like the Idealscope for this one shows a bit more leakage the one immediately above.

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-1181459.htm
1.51 G VS2 GIA XXX 2.6 HCA $13,953
62.5% depth
56% table
40.8 pavilion angle
35.5 crown angle
My concern is the 2.6 HCA, the "expect selection" rather than "cut above" from whiteflash. What's the deal? Is this why the price is so low? What am I missing? Where will I see a degradation in "performance"?


Can anyone provide their input on these stones and maybe educate me why you think the prices are so wildly different and how whiteflash could characterize a stone as second tier (ie "expert selection" rather than "a cut above") yet the stone has the highest rating either from AGS or GIA respectively and the HCA score is in the 1's. How much should I even consider HCA (the prices seem to reflect HCA)?

 

[yssie]

Re: How important is HCA score? Why such differences in $? H

HCA is an excellent starting point. A score under 2 (my personal cutoff is more like 3) means that the stone is "likely worth further investigation". It does not say that a stone that scores under 2 is automatically a winner, nor does it say that a stone that scores over 2 is automatically a loser. Stones w/ different scores (0.5, 1.5, 2.5) will have different personalities, but may all be objectively beautiful! Remember that HCA only considers 4 inputs that have been averaged around 8 sections of stone (and then rounded if GIA), it doesn't consider optical symmetry or other proportions or girdle treatments - all of which can have significant impact on how the stone looks and returns light.

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I'm trying to decide on a diamond in approximately the 1.5 carat size.

I definitely stress the cut and life of the diamond far above clarity and I do want H or better color (preferably G).

I've been focusing on H&A diamonds because I like the contrast they give in the lights/darks areas in the table.

Now, I'm trying to wrap my head around some prices I see and trying to figure out what I'm dealing with and what's the best, most brilliant (yet "colorless") stone I can find that's eye-clean.

Some stones I'm considering (All H&A) are:
http://www.goodoldgold.com/diamond/8892/
1.5ct G SI1, AGS0 but a 2.8 HCA for $15,600
61.4 depth
55.4 table
40.8 pavilion angle
34.3 crown angle
My concern with this one is the 2.8 HCA and the actual diamond pic doesn't show good contrast in the table like the rest of the stones in this post. What should I expect in relative performance for a 2.8 HCA vs something below 1.5? Also, despite the AGS0, it only gets a very good on the GIA grading included with the stone. Also, what's up with the DiamXray and no IdealScope? There's no way this thing could have zero leakage (no white spots) like the DiamXray seems to indicate, right? Lastly, the feather inclusion is clearly visible in the photo supplied, do you think that'd be eye clean? Sarah from GOG says it's not.

Yes way This is "brillianteering" - "painting" and "digging" - it's where the angles at which the crown and pavilion facets meet at the girdle have been altered from the "traditional" design. You can read more here http://www.goodoldgold.com/4Cs/NewCutGrading/PaintingandDigging/
This thread links pics and video [URL='https://www.pricescope.com/community/threads/few-questions-for-a-newbie-about-cut-and-optics.172972/#post-3147739?hilit=painting#p3147739']https://www.pricescope.com/community/threads/few-questions-for-a-newbie-about-cut-and-optics.172972/#post-3147739?hilit=painting#p3147739[/URL]

Re. eyeclean - we can't say anything at all about whether a given inclusion is visible from a given distance IRL from pics. Your rep, who has the stone in hand, has answered this question for you. Depending on what type of setting you're considering, if you're interested in the stone you could ask if the girdle inclusion can be pronged.

DiamX is GOG's version of IS pic - same thing, just better/easier to get photos with good detail. Use them the same way. GIA has a zero-tolerance policy for brillianteering, some agree w/ it and some don't - but that's not a GIA report anyway,just facetware estimate based on scan results. You can play with facetware yourself here https://www.gia.edu/facetware/ . The tutorials & thread go into it more.

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http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2671391.htm
1.518 G SI1, AGS0 1.4 HCA for $16,800
61.9 depth
55.0 table
40.6 pavilion angle
35.6 crown angle
My concern here is despite the AGS0, H&A, its listed as only "expert selection" from whiteflash rather than a cut above. Why? Also, do I see an inclusion right in the center of the table? I think that may be eye-visible and cause me to eliminate it.

The plot diagram on the AGS shows the crystal in the middle of the table... you can see it, though it's pretty faint - not a great scan of the report. Ask if the stone is clean to your personal requirements (clean from face-up from 5"? from 12"? from the sides as well?)

It's not being sold as H&A - if it was you'd have a hearts photo. To make the ACA line stones must have A) proportions that fall within certain restricted ranges, and B) precision of cut that yields optical symmetry such that you see those picture perfect hearts and arrows patterns when you look at the stone through a H&A scope. This stone failed one of those requirements, WF will be able to give you more detail. Sometimes the "reasons for failure" have a visible, visual impact, sometimes they don't - in this case they definitely don't.

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http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2709001.htm
1.52 H, VS2 AGS0 1.1 HCA $18,479
61.2% depth
57% table
40.7 pavilion angle
34.7 crown angle
My concern here is the picture of the diamond shows a lack of detail. Things seem washed out in general and around the perimeter I can't really see contrast in the facets compared to other stones. For instance, check out the difference in this stone's busyness compared to the next one.
http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2666574.htm
There's so much more going on in this one, but the inclusions in the table may be a bit much for me.

Slight differences in photography setup/lighting and/or differences in post-photography editing/printing - nothing to do with the stones at all, not to worry. The stone will not be "washed out" or have "indistinct" features IRL. Hearts are nice.

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http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2708998.htm
1.51 H VS2 AGS0 1.6 HCA $18,345
61.8% depth
57.0% table
40.8 pavilion angle
34.9 crown angle
No real comments. It looks like the Idealscope for this one shows a bit more leakage the one immediately above.

ISs on both look picture perfect They can be tough, and you wonder what this variation means and whether that difference is significant... after looking at several hundred it gets easier to distinguish

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[yssie]

Re: How important is HCA score? Why such differences in $? H

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-1181459.htm
1.51 G VS2 GIA XXX 2.6 HCA $13,953
62.5% depth
56% table
40.8 pavilion angle
35.5 crown angle
My concern is the 2.6 HCA, the "expect selection" rather than "cut above" from whiteflash. What's the deal? Is this why the price is so low? What am I missing? Where will I see a degradation in "performance"?

IS is not picture perfect like the others you've got here, photos suggest imperfect (meaning just non-H&A, not *ugly*) optical symmetry, proportions exclude it from ACA line, and it has a GIA report rather than the pedigreed AGS Platinum report (AGS0s command a premium). It is also an older GIA report, stone is likely a trade-in - I would require that the stone either be sent back to GIA for a new report, or I would plan on an independent inspection to confirm that the condition of the stone is exactly as described on the report, which is what you are paying for (ie. confirm that there aren't nicks/scratches/chips from setting/wear in the years since the report was issued). The price reflects all of this.

There are several reasons to buy a branded stone - you are guaranteed to get a visually beautiful stone, you are guaranteed a certain level of "mindclean-ness", it's an easy purchase process, branded stones usually come with generous policies re. upgrade/buyback/etc... depending on what's important to you this one may or may not be a great fit. If you are looking for a truly mind-clean stone, if you want to know that your stone is precision-cut to exhibit excellent optical symmetry - whether or not you can see the difference - then this stone is obviously not a good fit. If all you want is a beautiful stone, and mind-clean is not so important, if this one checks out it could be a great deal - you get the generous policies at a great pricepoint without sacrificing visible performance.

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Can anyone provide their input on these stones and maybe educate me why you think the prices are so wildly different and how whiteflash could characterize a stone as second tier (ie "expert selection" rather than "a cut above") yet the stone has the highest rating either from AGS or GIA respectively and the HCA score is in the 1's. How much should I even consider HCA (the prices seem to reflect HCA)?

 

[John P]

Re: How important is HCA score? Why such differences in $? H

http://www.goodoldgold.com/diamond/8892/
1.5ct G SI1, AGS0 but a 2.8 HCA for $15,600
61.4 depth
55.4 table
40.8 pavilion angle
34.3 crown angle
My concern with this one is the 2.8 HCA and the actual diamond pic doesn't show good contrast in the table like the rest of the stones in this post. What should I expect in relative performance for a 2.8 HCA vs something below 1.5?

FYI: Those measurements should result in HCA 1.1

 

[Buschman98]

Re: How important is HCA score? Why such differences in $? H

Thank you for pointing that out. I entered the numbers incorrectly. Its actually 41.13 pavilion angle, 34.65 crown angle.

 

[Gypsy]

Re: How important is HCA score? Why such differences in $? H

Also, the HCA is a useful but limited tool. It's ALWAYS (in every single case) irrelevant AND trumped by the AGS0.

 

[MichelleCarmen]

Re: How important is HCA score? Why such differences in $? H

Hi,

I've owned both Expert Selection and ACA stones (of the same size) and they're EQUALLY as beautiful! I couldn't tell the difference and the ES looked nearly perfect under my ideal scope and I was able to go up in color & clarity by going with an ES. Personally, I'd go with either of them depending upon what I could afford and which stones had the color/clarity/size I would like, but not consider any stone that is virtual selection. Make sure WF (or whichever vendor) has the stone on-hand so they can give you input if you decide to request it.

 

[Buschman98]

Re: How important is HCA score? Why such differences in $? H

So, I'm starting to lean towards:

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2671391.htm
1.518 G SI1, AGS0 1.4 HCA for $16,800
61.9 depth
55.0 table
40.6 pavilion angle
35.6 crown angle

I've spent a long, long time discussing the diamond with someone from WF and she indicated that the diamond was probably not given the "ACA" grade because of the crown angle but stated the pavilion angle offsets that nicely for good light performance. Can anyone comment on the legitimacy of that at all? I've attached a hearts image they also sent me.

Speaking with the rep from WF, she mentioned inclusions may be visible from the side and that it's a "typical" SI1. So, that also has me slightly nervous. I'd rather take G color and SI1 if I can't see the inclusions over an H VS2, but that's because I evaluated an I EGL America rated diamond that I felt was too yellow and I'm trying to get farther away from it.

Please impart any personal opinions or advice you may have! I've reserved the diamond and I'm getting more nervous by the minute!

 

[Gypsy]

Re: How important is HCA score? Why such differences in $? H

EGL is typically 2 color grades below GIA standards. I'd still take the G though.

Clarity is graded table up only so yes, seeing an inclusion from the side is normal in an SI or even a VS2 stone depending on the nature and placement of the inclusions. It's a birthmark though, you will always know it is your stone. Plus the setting usually covers a LOT of the profile of a stone up so most people don't see their inclusions at all when set.

 

[yssie]

Re: How important is HCA score? Why such differences in $? H

So, I'm starting to lean towards:

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2671391.htm
1.518 G SI1, AGS0 1.4 HCA for $16,800
61.9 depth
55.0 table
40.6 pavilion angle
35.6 crown angle

I've spent a long, long time discussing the diamond with someone from WF and she indicated that the diamond was probably not given the "ACA" grade because of the crown angle but stated the pavilion angle offsets that nicely for good light performance. Can anyone comment on the legitimacy of that at all? Just as she saidI've attached a hearts image they also sent me hearts look nice .

Speaking with the rep from WF, she mentioned inclusions may be visible from the side and that it's a "typical" SI1. So, that also has me slightly nervous. I'd rather take G color and SI1 if I can't see the inclusions over an H VS2, but that's because I evaluated an I EGL America rated diamond that I felt was too yellow and I'm trying to get farther away from it. Ditto Gypsy.

Please impart any personal opinions or advice you may have! I've reserved the diamond and I'm getting more nervous by the minute!

 

[Christina...]

Re: How important is HCA score? Why such differences in $? H

I just recently purchased a diamond with very similar proportions and it's full of life and has tons of fire, which was primarily what I was looking for. I love the profile view too, with the small table and steep crown, to me, it's exactly how a diamond should look in profile. I think that you are making a lovely choice and I don't think that you will be disappointed at all! Can't wait to see what your final decision is!

 

[Buschman98]

Re: How important is HCA score? Why such differences in $? H

Thanks so much for the reassurance, Christina!

And Yssie, I wanted to specifically thank you so very much for your extremely comprehensive and informative post! I had no idea I was looking at such a painted diamond in the GOG stone and your links were so educational and made that abundantly clear to me. I'm very disappointed that the GOG rep I interfaced with didn't mention that at all. Seems like a fairly shady move overall.

I've basically only been looking at stones that are returned to me through the PS search engine. Does anyone have any other diamond resource recommendations? I see people mentioning IDJ but I'm not totally sure who/what that even is. I saw an idjeweleryonline.com - is that what people are referring to? Their stones have been extremely skeptical because they supply no actual images of the stone, no ASET images from what I can tell, only show the GIA cert, and their prices seem too low for what the claim the stones are. So, I feel like the truth is in the missing details.

Thanks again, everyone! You're definitely helping to make this at least a little less stressful and I've learned so much through this site!

 

[yssie]

Re: How important is HCA score? Why such differences in $? H

You're welcome

I guess it can be difficult to pick and choose how much detail to go into sometimes, too little = customer feels dissatisfied or cheated, too much = overload! It's easier on here, since it's a safe assumption that a buyer wouldn't be here if he/she didn't want more info, y'know? In any case I'd definitely mention that you're looking for as much detail as possible next time you chat, hopefully that will get things moving!


IDJ (that's the right site) does have good prices, I've never worked with them but my understanding is that the more particular customers should make clear that they are PSers. They aren't the sort of vendor that caters specifically to the cut nut market. For lower pricepoints than GOG/WF/etc. I prefer www.jamesallen.com - the site has pics that make it easy to search and they do have a H&A line, policies are not as generous though.



So here are all the stones you've been looking at. I'd toss these four - A for all the reasons listed, B b/c I don't see virtue in paying for higher than appreciable clarity, C b/c if you're okay with Gs and Hs why spend more on higher colour, D b/c H has same diam/flavour/stats and is a couple hundred less and that's a really nice dinner with lots of wine

A)
1.5 E VS2 GIA EX $17.7k http://www.goodoldgold.com/diamond/9352/
Poor optical symmetry, some leakage under table, limited policies, strong blue fluor
36/41.2/57/85(GIA)

B)
1.348 H VS1 ACA $14.1k http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2696781.htm
7.09x7.10mm
34.8/40.9/55.3/77

C)
1.312 F VS2 ACA $15.2k http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2787736.htm
7.04x7.06mm
34.9/40.9/56/78

D)
1.516 H VS2 ACA $18.5k http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2709001.htm
7.38x7.41mm
34.7/40.7/57/77


If there's a setting you like at GOG then just get E and call it a day - it's a very nice stone! If you're not sure, or you prefer one from WF, other things to consider - do you want a H&A stone? What price range would you prefer to stay in - K is a nice one, it'll be visibly smaller than the others you're looking at though (and memorably, IMO - I mean that if you see it, take it away, and look at the other, you'll likely remember the one as bigger)

E)
1.5 G SI1 GOG H&A $15.6k http://www.goodoldgold.com/diamond/8892/
If the inclusion is prongable (and a pronged inclusion is mind-clean for you) and if you like/don't object to the slightly different look this is a nice find
7.42x7.43mm
34.6/41.1/55.3/78

F)
1.532 I VS2 ACA $13.9k http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2708997.htm
Slight leakage under table that Gypsy pointed out, won't have any effect at all on real-world performance but may not be "mind-clean" for nitpickier PSers...
7.38x7.4mm
34.9/40.8/57/76

G)
1.51 G VS2 ES $13.9k http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-1181459.htm
Great value for money if you are looking for a visually beautiful but not necessarily "mind clean" stone, with generous vendor policies
7.29x7.33mm
35.5/40.8/56/80

H)
1.505 H VS2 ACA $18.3k http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2708998.htm
7.34x7.37mm
34.9/40.8/56.5/77

I)
1.518 G SI1 ES $16.9k http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2671391.htm
Reserved - for you? Inclusion in middle of the table - is it clean to your specifications (clean from 5" face-up, 12", sides as well? whatever you care about)
7.36x7.38mm
35.6/40.6/55.3/76

J)
1.503 H SI1 ES $15.2k http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2666574.htm
Interesting stone. This proportions "type" is my personal favourite - whether a stone returns white or coloured light depends on the lighting type, in some lights (spotlights) all stones will show coloured light, in other types (diffuse office lights) all stones are white and bright. In "mixed" lights some stones, depending on proportions and faceting, will err toward white light return while others like this high crown/small table/shallower pav type err toward coloured light return
But, is it eyeclean for you?
7.29x7.33mm
36.2/40.6/56.3/80

K)
1.332 G VS2 ACA $14.3k http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2721311.htm
7.06x7.08mm
34.8/40.8/56.3/77

 

[yssie]

Re: How important is HCA score? Why such differences in $? H

couple from JA (they will provide 3 ISs + gemologist reviews free)

1.55 H VS2 GIA EX $14.8k http://www.jamesallen.com/diamonds/H-VS2-Excellent-Cut-Round-Diamond-1491518.asp
7.49x7.53mm
33.5/40.8/56/75

1.5 G VS2 GIA EX $16.4k http://www.jamesallen.com/diamonds/G-VS2-Excellent-Cut-Round-Diamond-1426609.asp
7.34x7.37mm
34.5/41/54/75

1.51 I VS2 GIA EX $12.5k http://www.jamesallen.com/diamonds/I-VS2-Excellent-Cut-Round-Diamond-1447577.asp
7.37x7.53mm
35/40.8/56/75

 

[TitanCi]

Re: How important is HCA score? Why such differences in $? H

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-1181459.htm
1.51 G VS2 GIA XXX 2.6 HCA $13,953
62.5% depth
56% table
40.8 pavilion angle
35.5 crown angle
My concern is the 2.6 HCA, the "expect selection" rather than "cut above" from whiteflash. What's the deal? Is this why the price is so low? What am I missing? Where will I see a degradation in "performance"?


I was looking at this stone too, like the OP. Does the faint fluoro have an impact on it's price??

 

[John P]

Re: How important is HCA score? Why such differences in $? H

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-1181459.htm
1.51 G VS2 GIA XXX 2.6 HCA $13,953
62.5% depth
56% table
40.8 pavilion angle
35.5 crown angle
My concern is the 2.6 HCA, the "expect selection" rather than "cut above" from whiteflash. What's the deal? Is this why the price is so low? What am I missing? Where will I see a degradation in "performance"?

I was looking at this stone too, like the OP. Does the faint fluoro have an impact on it's price??

This diamond has a Tiffany-esque set of proportions; pairing a slightly high crown with a Tolkowsky pavilion. If the CA was just 0.4 of a degree less the HCA score would move to 1.6. Regarding ES versus ACA, the logical answer is that the diamond lacks the precision-cutting WF would require for the stone to be included in their ACA brand. The faint fluorescence isn't an issue. If it results in a discount I'm sure it's fractional.

 

[Buschman98]

Re: How important is HCA score? Why such differences in $? H

Thanks for all of the help. I ended up selecting the "I)" stone. After getting a bunch of feedback from WF rep and a graduate gemologist at WF, I felt comfortable that the stone was eye clean and went with it. Also, A few additional photos were sent over of the stone from the top and sides that just looked wonderful.

Thanks again for all your help. I'll be sure to post pictures of it online when I receive the ring. I'm having one custom made so it's going to be a few weeks before I have pics.

 

[diamondseeker2006]

Re: How important is HCA score? Why such differences in $? H

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-1181459.htm
1.51 G VS2 GIA XXX 2.6 HCA $13,953
62.5% depth
56% table
40.8 pavilion angle
35.5 crown angle
My concern is the 2.6 HCA, the "expect selection" rather than "cut above" from whiteflash. What's the deal? Is this why the price is so low? What am I missing? Where will I see a degradation in "performance"?


I was looking at this stone too, like the OP. Does the faint fluoro have an impact on it's price??

I will also add that you need to be paying attention to the diameter measurements. This one is only 7.29-7.33mm probably because of the depth. I prefer to find 1.5's closer to or above 7.4mm and often these are going to have depths of 60-62.0. I would not buy this stone because of the small diameter.