Whiteflash A cut Above

[Michel]

As I have now been researching and learning about diamonds for months, I really need to make a decision.

In the Whiteflash ACA range - do I need to pay attention to the numbers (table width etc), or can I just get any from the ACA with the knowledge it will be a fantastic cut?

Also, the settings on that site are very cheap - are they any good?

Thanks (and sorry for all these threads!)

 

[Maisie]

I have had two ACA diamonds and they were beautiful. I trust their judgement when they decide to put these diamonds in the ACA range. They are the best they have.

The settings are definitely well made and worth the money.

 

[Michel]

I ask because I keep putting specs of their diamonds into the Pricescope HCA and I cannot get above Very Good for Spread, whereas I get excellent for all the other areas. Any thoughts?

 

[polo01]

I am actually looking at an ACA princess cut right now too.. I need to make my decision but I also looking at other places for the same specs but not ACA.

 

[Michel]

And!

In some cases I am only getting Excellent for one of them!

 

[bem3231]

Date: 2/3/2008 11:52:27 AM
Author: Michel
I ask because I keep putting specs of their diamonds into the Pricescope HCA and I cannot get above Very Good for Spread, whereas I get excellent for all the other areas. Any thoughts?

I will let an expert chime in but I''ve read several times that all but the shallowest stones can be expected to get very good rather than excellent on spread. I think that these shallower stones are better suited to a pendant or earrings than a ring, so if you''re purchasing for a ring probably very good rather than excellent spread is preferable.

For what it''s worth, I''ve put about 250 stones through the HCA in the past few months and I have never gotten one with excellent spread (which is fine, because I wasn''t looking for one!).

Hope that helps!

 

[polo01]

goodoldgold.com is getting an AGS 0 princess cut in for me to see. Its slightly less then an ACA. So I am going to compare the two

 

[iheartscience]

The HCA is for rounds only. If you are inputting princess cut numbers into it, the results are likely to be wonky. Just an FYI.

 

[Michel]

Don''t worry, I was inputting Round Brill.

Bem - thank you ever so much for that information. If it is correct, then it makes the search a ahwole lot easier! There are loads of EX-EX-EX-VG from Good Old Gold, Whiteflash and james Allen - yippee!!

Can someone confirm it please?

 

[Michel]

Also,

On the HCA page is says:

Your own personal preference may be for a diamond with an HCA score of 1.5 more rather than one with a lower score of say 0.5.

How can this be - can someone explain? Why isn''t lower better?

Thanks

 

[Allison D.]

Michel, I''m assuming your question is relative to a round stone if you''re using the HCA to help you narrow the field.

The HCA is really useful as a weeding tool to help you narrow down your selections, but it doesn''t actually evaluate diamonds. It uses a few measurements to predict possible performance. It''s not meant as a selection tool but rather as a rejection tool.

In response to your question about A Cut Above stones and paying attention to the numbers, you''ll probably find most numbers to be pretty similar becuase A Cut Above stones are cut within a very specific and tight range of proportions that Brian Gavin believes produce the best possible visual balance across a broad range of lighting situations. Diamonds that don''t meet this his exacting standard of visual balance and performance don''t earn the A Cut Above designation.

 

[bem3231]

Date: 2/3/2008 12:16:11 PM
Author: Michel
Also,


On the HCA page is says:


Your own personal preference may be for a diamond with an HCA score of 1.5 more rather than one with a lower score of say 0.5.


How can this be - can someone explain? Why isn''t lower better?


Thanks

Again, I defer to the experts, but I think the jist of it is that numbers plugged into a formula cannot compete with the vagaries of light performance as they relate to overall beauty that the human eye can register. The HCA is meant to ''weed out'' poor performers but I think that the consensus here is that beyond that you need to use other factors to decide on ''the one''.

I read that bit about spread again in a thread within the past few days, but I can''t find it now. Maybe try doing a board search with ''HCA spread''?

 

[Allison D.]

Date: 2/3/2008 12:16:11 PM
Author: Michel
Also,

On the HCA page is says:

Your own personal preference may be for a diamond with an HCA score of 1.5 more rather than one with a lower score of say 0.5.

How can this be - can someone explain? Why isn''t lower better?

Thanks

It might help to think of the HCA as a pass/fail predictor.....

Anything under 2 is more likely to score a pass; stones above two are less likely to score a pass.

It''s a weeding tool, not an evaluation tool. It''s mean to help you narrow down the pool of possible candidates to those that have the rough makings of well-performing stones, but it''s not mean to say "this stone will be better than another stone".

That job is meant for your eyes.

 

[Lord Summerisle]

the HCA only give Excellent for spread for those diamonds with a depth less than 60.3%

there are some ACA diamonds that come under that line - the diamonds i purchased for my Wife is 59.9% and an ACA. I would say tho if your looking at around the 1ct mark then your less likely to find one with a depth that low, as cutters will be trying to get the weight over the 1ct mark. This isnt a bad thing too much. and the difference between a HCA Excllent of 60.1% and say a 60.5% very good could in the order of 0.01-0.02mm diameter.

I think very good depth is 60.4% upto at least 62.9%

The ACA cut parameters are a very narrow band right in the middle of the AGS 0 cut grade - so i''d say, yes you can be assured that your going to get a very good cut - if you plug the carat/colour/clarity your looking at in the search box above, tick the H&A box and click the ''cut quality search'' box then pricescope will show you the HCA scores with the diamond listings.

 

[Ellen]

bem is correct on both how a stone can get EX in spread (my stone faces up just as it should, yet only gets a VG in spread), and about the HCA, as is Allison.

And yes, you can be safe with an ACA, if you don''t want to learn the ins and outs of reading IS pics and learning all the numbers.

 

[diamondseeker2006]

The answer is, no, you do not even need to put ACA stones in the HCA. The HCA, as far as I am concerned is to help screen GIA diamonds that are not in the ACA category or not graded by Good Old Gold as having ideal light return. I bought a matching pair of ACA''s for earrings, and I did have to look at numbers to match up a pair, but never did I once even think about putting them through the HCA, because all ACA''s will fall in the AGS0 box!!!

 

[Ellen]

Date: 2/3/2008 12:16:11 PM
Author: Michel
Also,

On the HCA page is says:

Your own personal preference may be for a diamond with an HCA score of 1.5 more rather than one with a lower score of say 0.5.

How can this be - can someone explain? Why isn''t lower better?

Thanks

Stones that get a score of say .05, will usually be shallow in depth, with shallow crown and pavillion angles. These stones may suffer from head shadow (your head blocks the light when looking close up, causing the stone to get darker), and scintillation may suffer a bit.

 

[Michel]

Thanks everyone - so what can I do as an online buyer?

Examine the x10 and the ideal scope?

I notice for, example, that the light escapes on a lower HCA number look ''softer'' than on higher ones.

For example, look at these two below. The first is a 0.8, the second a 1.5.

 

[Michel]

1.5...

 

[Paul-Antwerp]

Date: 2/3/2008 1:11:50 PM
Author: Ellen

Date: 2/3/2008 12:16:11 PM
Author: Michel
Also,

On the HCA page is says:

Your own personal preference may be for a diamond with an HCA score of 1.5 more rather than one with a lower score of say 0.5.

How can this be - can someone explain? Why isn''t lower better?

Thanks

Stones that get a score of say .05, will usually be shallow in depth, with shallow crown and pavillion angles. These stones may suffer from head shadow (your head blocks the light when looking close up, causing the stone to get darker), and scintillation may suffer a bit.

I do wonder if this is true. In other words, I think that this is absolutely not true. But maybe Garry can chime in here.

Live long,

 

[Michel]

The strange thing as well is that the two photos I ahve shown below, there being a big difference in the HCA score, there is no real difference in price - they are otherwise exactly the same!

is it normal not to expect a price difference? Are they so affected by colour, clarity etc that the real nitty gritty of a HCA score, if they are both ''ideal'' pales in insignificance?

 

[strmrdr]

Date: 2/3/2008 3:14:41 PM
Author: Michel
Thanks everyone - so what can I do as an online buyer?

Examine the x10 and the ideal scope?

I notice for, example, that the light escapes on a lower HCA number look ''softer'' than on higher ones.

For example, look at these two below. The first is a 0.8, the second a 1.5.

biggest difference in the 2 images is the stone is tilted towards the bottom of the image in the second and is fairly level in the 1st.

ACA''s in general have had good numbers but no vendor gets a pass, show me the data then I will tell ya what I think. (WF provides the data so no biggie)
Biggest disagreement has been in lgf% and painting(not being produced lately) which the hca doesn''t take into account anyway.

 

[strmrdr]

Date: 2/3/2008 3:40:43 PM
Author: Michel
The strange thing as well is that the two photos I ahve shown below, there being a big difference in the HCA score, there is no real difference in price - they are otherwise exactly the same!

is it normal not to expect a price difference? Are they so affected by colour, clarity etc that the real nitty gritty of a HCA score, if they are both 'ideal' pales in insignificance?

they are both excellent stones.... If the pavilion angle of the first is 40.5 or lower it needs to be checked for contrast issues if used in a ring.
HCA is an ok rejection tool nothing more, that needs too be used with caution.
I passes some combos that are better in earrings and pendants that are excellent stones just not for rings(contrast issues).
It rejects some combos that have been proven to be excellent performers with modern research.
The hca reflects Garry's opinion on what an excellent diamond should be and that doesn't always align with the rest of the world. LOL

 

[strmrdr]

Date: 2/3/2008 3:27:53 PM
Author: Paul-Antwerp
I do wonder if this is true. In other words, I think that this is absolutely not true. But maybe Garry can chime in here.

Live long,

.5 on the hca will pretty much always have a shallow pavilion and need to be checked by a trustworthy expert who understands ideal cuts.

 

[Ellen]

Date: 2/3/2008 3:27:53 PM
Author: Paul-Antwerp

Date: 2/3/2008 1:11:50 PM
Author: Ellen

Date: 2/3/2008 12:16:11 PM
Author: Michel
Also,

On the HCA page is says:

Your own personal preference may be for a diamond with an HCA score of 1.5 more rather than one with a lower score of say 0.5.

How can this be - can someone explain? Why isn''t lower better?

Thanks

Stones that get a score of say .05, will usually be shallow in depth, with shallow crown and pavillion angles. These stones may suffer from head shadow (your head blocks the light when looking close up, causing the stone to get darker), and scintillation may suffer a bit.

I do wonder if this is true. In other words, I think that this is absolutely not true. But maybe Garry can chime in here.

Live long,

This is what I understood him to say, from this: (taken from the HCA explanation that Gary posted on here)

Shallow stones (lower left on the chart) look darker if you have excellent close up vision because your head obstructs more light sources which makes a shallow diamond appear darker. But shallow diamonds have a bigger spread, and are great for pendants and earrings, where normal social viewing distances apply.

Stones near the center of the red region (the lowest scores) are least affected by symmetry variations. Alternatively hearts and arrows diamonds, which have excellent optical symmetry, but often HCA scores around 2, may out-perform diamonds with lesser symmetry and lower HCA scores.


If that is what you meant.


If you meant shallower stones with shallower crown and pavillion angles tend to get scores under 1, that has been my experience from the many, many such type stones I''ve plugged in it.

 

[diamondseeker2006]

Date: 2/3/2008 3:40:43 PM
Author: Michel
The strange thing as well is that the two photos I ahve shown below, there being a big difference in the HCA score, there is no real difference in price - they are otherwise exactly the same!

is it normal not to expect a price difference? Are they so affected by colour, clarity etc that the real nitty gritty of a HCA score, if they are both ''ideal'' pales in insignificance?

They are both ideal cut stones. Why would they have a price difference assuming they are the same size, color, and clarity? The HCA score has nothing to do with pricing. If the stones are graded ideal for light performance, then that is what you need to focus on. I think you are making this a little harder than it really is!

 

[Rhino]

Date: 2/3/2008 3:27:53 PM
Author: Paul-Antwerp

Date: 2/3/2008 1:11:50 PM
Author: Ellen

Date: 2/3/2008 12:16:11 PM
Author: Michel
Also,

On the HCA page is says:

Your own personal preference may be for a diamond with an HCA score of 1.5 more rather than one with a lower score of say 0.5.

How can this be - can someone explain? Why isn''t lower better?

Thanks

Stones that get a score of say .05, will usually be shallow in depth, with shallow crown and pavillion angles. These stones may suffer from head shadow (your head blocks the light when looking close up, causing the stone to get darker), and scintillation may suffer a bit.

I do wonder if this is true. In other words, I think that this is absolutely not true. But maybe Garry can chime in here.

Live long,

While I do not check diamonds in the HCA I have seen perfect instances where Ellen''s words are quite true and with diamonds that scored .5 and under on the HCA Paul.

Peace,

 

[Ellen]

Thanks for the "visual" confirmation Jon.

 

[Michel]

Ellen''s words have confused me, though. I do not know what to make of it now, then.... : /

 

[Garry H (Cut Nut)]

Date: 2/3/2008 4:01:46 PM
Author: strmrdr

Date: 2/3/2008 3:27:53 PM
Author: Paul-Antwerp
I do wonder if this is true. In other words, I think that this is absolutely not true. But maybe Garry can chime in here.

Live long,

.5 on the hca will pretty much always have a shallow pavilion and need to be checked by a trustworthy expert who understands ideal cuts.

Not true Storm. 41 degree pavilions are easily possible with various shallow crown angles - and they will have excellent spreads.
But the idea that you aim for a lower HCa is clearly wrong.

HCA is for rejection.
The only time a to aim for a shallower stone is if it is for earrings and pendants.