H&A or idealscope?

[slycatty]

Which is a better indicator of diamond performance: hearts and arrows or idealscope images?
Thanks

 

[Dreamer_D]

Date: 3/21/2010 1:28:44 AM
Author:slycatty
Which is a better indicator of diamond performance: hearts and arrows or idealscope images?
Thanks

An ideal scope image.... but I guess the answer is more complicated

H&A is an indicator of the symmetry and the precision of the cut, which is technically not related to optical performance. Optical performance is a function of the angles of the cut.

An ideal scope image is an indicator of the light return of the diamond and is therefore an indicator of its optical performance.

Although buying an H&A diamond means, the vast majority of the time, that you will also have an optically superiour performer -- particularly if it is a branded H&A -- you can also have an optically great performing diamond that is *not* an H&A. So, even with an H&A diamond you will want an IS image to double check and confirm its optical performance (if possible, you can also see it in person of have a trusted expert view the diamond to asses its optics).

 

[Lorelei]

Date: 3/21/2010 1:28:44 AM
Author:slycatty
Which is a better indicator of diamond performance: hearts and arrows or idealscope images?
Thanks

I like Idealscope images to check for light leakage, ASET show light return and leakage. If evaluating a h&a diamond then images of both hearts and arrows are essential in order to check the overall cut precision.

 

[stone-cold11]

idealscope image. H&A is just a measure of cut precision, a stone with a H&A image can still be leaky if the angles are not complimentary.

 

[slycatty]

Thanks guys. So what''s the advantage of the perfect symmetry and the perfectly shaped hearts and arrows?

 

[Regular Guy]

Lorelie or others tend to be smart to point you to sensitive tech discussions on this.

There is some level of controversy about the value of H&A. Some say:

- it adds nothing
- in combination with good angles ensuring light performance, it adds scintillation
- it''s like having better than visible clarity (i.e., VVS or IF type)
- it helps check the goodness of the light performance, from the point of view that a good IS doesn''t guarantee top light performance, but like a "loaded car," one that has more features might suggest the intention was there to provide all the optimizing that could be available with the diamond
- it can''t hurt, and might help
- by some analysis, it costs virtually nothing to add...so you just look for the feature

So...there''s some thoughts about H&A...

 

[Dreamer_D]

Date: 3/21/2010 4:06:39 PM
Author: slycatty
Thanks guys. So what''s the advantage of the perfect symmetry and the perfectly shaped hearts and arrows?

I think it is a mind thing, like knowing you got the best of the best. Like buying the name brand over the generic version. And it makes the facet patterns purdy

 

[Lorelei]

Date: 3/21/2010 4:21:33 PM
Author: Regular Guy
Lorelie or others tend to be smart to point you to sensitive tech discussions on this.

There is some level of controversy about the value of H&A. Some say:

- it adds nothing
- in combination with good angles ensuring light performance, it adds scintillation
- it's like having better than visible clarity (i.e., VVS or IF type)
- it helps check the goodness of the light performance, from the point of view that a good IS doesn't guarantee top light performance, but like a 'loaded car,' one that has more features might suggest the intention was there to provide all the optimizing that could be available with the diamond
- it can't hurt, and might help
- by some analysis, it costs virtually nothing to add...so you just look for the feature

So...there's some thoughts about H&A...

Thanks Ira!

Thats a great overview from Ira above, also this precision tutorial is one of my particular favourites on cut precision and h&a patterning.

This paragraph is quoted from the article above and is a good summary.

"Cut Precision fine-tunes diamonds which already enjoy top performance. The better-defined contrast pattern can create sharper on-off scintillation and more primary colors in dispersion (less pastels and earth tones). Precision cutting maximizes the return of all available light, even in softer lighting conditions. This is a logical result of all of the facets, the tiny mirrors inside the diamond, brought into precise alignment with each other. Face up color can be improved when light gets in and out of a diamond with more intensity. This can be noted in many diamonds with above-average performance. High performance coupled with top cut precision enhances the effect even more."

 

[yssie]

Date: 3/21/2010 4:28:58 PM
Author: Lorelei

Thanks Ira!

Thats a great overview from Ira above, also this precision tutorial is one of my particular favourites on cut precision and h&a patterning.

This paragraph is quoted from the article above and is a good summary.

'Cut Precision fine-tunes diamonds which already enjoy top performance. The better-defined contrast pattern can create sharper on-off scintillation and more primary colors in dispersion (less pastels and earth tones). Precision cutting maximizes the return of all available light, even in softer lighting conditions. This is a logical result of all of the facets, the tiny mirrors inside the diamond, brought into precise alignment with each other. Face up color can be improved when light gets in and out of a diamond with more intensity. This can be noted in many diamonds with above-average performance. High performance coupled with top cut precision enhances the effect even more.'

Lorelei, I'm going to have to disagree with you and HPD on the highlighted-


1. Absolutely not. If dispersion occurs, it outputs a very specific, static set of wavelengths in a very specific, static order. There is absolutely no way dispersion can be "tweaked" to return more primary colours and fewer "pastels/earth tones". Most of the energy (read: light) is returned to the viewer in the PRIMARY refraction, so any manipulations of dispersion effects would have necessarily little impact.


2. No. Precision cutting to achieve H&A (as described in the article) results in perfect optical symmetry. This means only that the faceting is such that if one takes a radial cross section, one will find that perfect symmetry (in addition to meet point symmetry as noted on lab certs). The presence of this optical symmetry itself - all these tiny mirrors in perfect alignment - does not in any way guarantee excellent light return, it guarantees symmetric patterning and a level of symmetry in the primary light output of those facets, because that's what optics physics dictates. You can certainly have a diamond that maximally outputs light without this perfect symmetry in faceting; statements like the above are misleading in that they ascribe to the existence of H&A performance effects that are actually the direct results of the other requirements of a brand of H&A diamond. Purchasing a diamond that has been precision cut to achieve H&A and that also satisfies the other angle and proportion requirements of most H&A brands (infinity, ACA, GOG sig., BGD H&A, HOF...) is an easy way to get a top performer, but there's no causal relationship between the two.

 

[Garry H (Cut Nut)]

Date: 3/21/2010 6:29:18 PM
Author: yssie

Date: 3/21/2010 4:28:58 PM
Author: Lorelei

Thanks Ira!

Thats a great overview from Ira above, also this precision tutorial is one of my particular favourites on cut precision and h&a patterning.

This paragraph is quoted from the article above and is a good summary.

''Cut Precision fine-tunes diamonds which already enjoy top performance. The better-defined contrast pattern can create sharper on-off scintillation and more primary colors in dispersion (less pastels and earth tones). Precision cutting maximizes the return of all available light, even in softer lighting conditions. This is a logical result of all of the facets, the tiny mirrors inside the diamond, brought into precise alignment with each other. Face up color can be improved when light gets in and out of a diamond with more intensity. This can be noted in many diamonds with above-average performance. High performance coupled with top cut precision enhances the effect even more.''

Lorelei, I''m going to have to disagree with you and HPD on the highlighted-


1. Absolutely not. If dispersion occurs, it outputs a very specific, static set of wavelengths in a very specific, static order. There is absolutely no way dispersion can be ''tweaked'' to return more primary colours and fewer ''pastels/earth tones''.

This is exactly true Yssie - the colors caused by dispersion may only be those from the rainbow. The benefit of high symmetry is more likely a certain crispness and larger flashes from larger virtual facets (but flash size can be more effected by the factor of the lower girdle length then symmetry)