Sparkle vs. Symmetry in H&A diamonds

[orangutan]

Hi all,

I am fairly new to the diamond buying experience, but have been researching it for the past week or so. A couple of questions:

1)In the Pricescope search, I found many Ideal H&A that met my criteria. My question was that even though all these diamonds are considered Ideal H&A, all that means is that you see hearts and arrows due to the symmetry of the diamond. However, the actual sparkle/brilliance/fire is determined by the crown and pavilion angles, correct?

2)Does that mean that one needs Sarin reports or Brilliancescope reports to determine how much each diamond will shine?

3)If two diamonds have the same symmetry and same measurements in terms of table and depth, is it still possible for one to be dull and the other to sparkle depending on the angles? What is the best way to confirm this, get Sarin reports on every diamond I''m interested in?

Sorry for the silly questions, but I''m new to this and there are >$1000 price variations for diamonds with identical color/quality and table/girdle measurements.

Thanks, look forward to hearing from y''all.

 

[valeria101]

Trying to take the points in some order...

#3 is correct

#1 ans #2 would be better understood in one lump: the H&A pattern tells allot of things - great symmetry and facet proportions aranged such that optical properties give top "sparkle" to the stone. Not all RBCs proportions yield "correct" H&A patterns regardless of proportions (as you seem to imply in #1). There are no "dull" H&A diamonds (compared to non H&A). The pattern itself was no developed as an end in itself bu emmerged by chance from the effort to determine optimal cut proportions for maximum light return...

However, not all H&A are created equal, and not all non H&A diamond are complete dogs. For this reason, the H&A pattern is an approximation of what direct optical analysis tells. To know what the optical "performance" (= light return) of a diamond is, either the Ideal Scope (or it's versions) or Brilliance scope does the trick. Isee2 - the same, plus a mark on symmetry. Once you ave any such direct optical analysis, any approximation of optical performance "by numbers" (Sarin) can only be less accurate. Sarin can tell symmetry (but not as well as the cert)... but it is always a long shoot from any set of numbers to optics.

Does this make sense ?

As for price variations... you bet. If you look among non "known H&A" it gets scary indeed.

 

[pqcollectibles]

Hearts and Arrows patterns are the result of precise internal optical symmetry. That optimum internal optical symmetry is achieved within a range of complimentary crown and pavillion angles. Sometimes, the cutter's quest for the patterns pushes the finished diamond beyond the limits of Ideal parameters, such as the 8* Brand. 8*'s are often not Ideal yet out perform many Ideal Cuts. There are Hearts and Arrows diamonds that are Ideal Cuts. There are Ideal Cuts that are not true Hearts and Arrows diamonds, that are great performers.

There's a thread addressing Cut issues you might want to read. It' kinda technical, but I have been enjoying reading it myself.

https://www.pricescope.com/community/threads/another-gia-press-release-on-diamond-cut-research.12787/

It is very important to get Sarin/OGI information on any diamond as part of the decision making process. You also want to see Ideal Scope images and the Hearts and Arrows patterns. Hearts and Arrows is used as a marketing ploy to unsuspecting consumers.

Many diamonds are laser inscribed on the girdle "Hearts and Arrows" or "H&A" prior to submission to the Grading Lab. The Grading Labs do not grade for the Hearts and Arrows patterns. The note on the Certs is just a notation that the inscription was present.

 

[orangutan]

Thanks Valeria and PQ,

So, what are some recommended websites that include an optical analysis of their products?

So far I've looked at:
GOG
superbcert

Any other suggestions? Thanks in advance.

 

[pqcollectibles]

I believe Nice Ice evaluates diamonds using the Brilliance Scope and will provide results upon request. Nice Ice does perform a DiamCalc ray tracing based on actual measurements of a diamond to show how light will refract in the diamond.

 

[mdx]

Hi orangutan

Sarin results are important in that you are able to determine that your choice has dimensions within a range of known good performers. Do consult a suitable qualified gemologist to interpret the finer details of the Sarin report.

I certainly would not use a Brilliant scope score as criteria for your final decision.
At this time it seems there is no universal agreement in the industry as to what these devises actually measure. In my opinion its unreasonable to assume that you can accurately measure electromagnetic radiation (visible light) using photographic methods especially digital.

Johan

 

[Rhino]

Mdx... what then is a photospectrometer?

 

[valeria101]

----------------
On 2/24/2004 2:57:34 PM orangutan wrote:

Thanks Valeria and PQ,

So, what are some recommended websites that include an optical analysis of their products?

So far I've looked at:
GOG
Superbcert

Any other suggestions? Thanks in advance.----------------

There is already a list of sellers on the thread... I guess all sellers listing diamonds here would at least agree to provide at least an IdealScope picture and those crown and pavilion angles (no idea about Mondera bet it could work with them too). Although, all diamonds purchased with a return policy can be evaluated by an appraiser. I haven't seen DBOF motioned here so far, but I suppose they also use the BrillianceScope.

As far as I know, no instrument and/ or technique for evaluating a diamond's light return is 100% accepted throughout the industry, but the three cited here (BrillianceScope, Isee2 and the flavors of IdealScope) seem to give closely correlated results. I did not dismantle any of these tools to see what's inside, but given the cost and complexity of using them to communicate cut quality to buyers, I doubt any seller would be crazy enough to use them if they were simple toys. Not the case...

I guess Mdx refers to the on-going debate about how the notions (and physiological perceptions) of brilliance, fire, light return, etc. are to be scientifically defined. In all honesty, this debate has by now reached far beyond reasonable buying concerns: it is important for the industry to adopt a precise standard - granted that - but as long as one extra notch on the Bscope does not result in a price premium, the ultimate precision is no longer a reason for outmost concern... I would say. Deciding to factor in cut quality is an important step: measuring harts and arrows down to the last tenth of a millimeter - oh well, I was hoping to make it clear that this is more important for sellers rather than buyers by now...

Sorry for the long, involved post. I hope it doesn't hurt

 

[mdx]

Hi Rhino

That a very good question, I suppose it would depend on the context. Does Photo relate to digital photography or is it from the Greek “Photos” for light.
There are a very broad range of instruments covering a variety of wavelengths and applications
I know about spectrophotometers and the discipline of optical radiation measurement, could it be a camera attached to spectrometer or another name for an electronic color comparator.
Please let us know.

Valeria 101

Although its obvious I don’t have much faith in the mentioned technologies this is really just my personal opinion I am sure in time a universally acceptable technology will happen.

The part that really worries me about these devises is the fact that consumers are shown a visual demonstration and graphs by retailers. There is no practical way that the result can be verified by an unbiased independent source, I know of no lab that uses them and only one appraiser Worldwide.

Even if the technologies where valid the consumer cannot verify the score.
Is this not like buying an uncertified diamond and excepting an in-house certification?

Granted visitors to this forum have the advantage of highly ethical vendors like Rhino but the principles of unbiased verification are a problem.
Johan

 

[valeria101]

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On 2/25/2004 5:54:00 AM mdx wrote:



Does Photo relate to digital photography or is it from the Greek “Photos” for light.

[...] the principles of unbiased verification are a problem.

----------------

I think that 'photo' relates here to non-photographic measurement technology being employed by the Bscope. As I understand, your previous post implied that the Bscope uses some digital photography technology to get it's scores... Is it so ? I'd rather believe the tool's technicals than the prefix of the name.

As for the verification issue: as far as I know the makers of the Bscope addressed it: buyers can have the scores verified for a fee. As long as labs not using Bscopes and Isee-s aren't these tools among the first ever made for the trade instead of a gemological lab? I am aware that most high (-er) tech tools have been traditionally developed to suit gemological laboratories and/or grading labs, but these two were not.

Do I believe them? More than I believe my so-so trained eye and very limited experience handling diamonds. From your posts alone, I can deduce that for any seller to acquire and use these tools makes for a strenuous selling technique (since, as you say, they are virtual pioneers in the usage of such sale arguments) and expensive deception. It is so much easier to sell diamonds making them sparkle over the counter and discounting them online... why bother !!! These are qualitative arguments: but I am an economist, not an engineer, so I find them worth the post

Why appraisers do not use Bscope and Isee - I think there were some comments about the legal and economic circumstances determining this (the demand for volume testing by Isee2 makers, for example).

Conclusion ? None of the light return tests strike me as an easy-sale pitch. Until they get there, I'll trust them as being better than a loupe and digital photo at representing diamond optics. Oh well ...

 

[orangutan]

Hi all,

Thanks for the comments everyone. Much appreciated. Couple more questions:

1)Where on PS are the list of sellers who provide optical intensity listed?

2)On the Brilliance Scope, what does white light, colored light and scintillation represent. Isn't most everyday light going to be white light?

 

[zeewer]

----------------
On 2/25/2004 12:53:48 PM orangutan wrote:

Hi all,

2)On the Brilliance Scope, what does white light, colored light and scintillation represent. Isn't most everyday light going to be white light?----------------

Refer to the the nice PriceScope tutorial here:
http://diamonds.pricescope.com/brill.asp

 

[pqcollectibles]

----------------
On 2/25/2004 12:53:48 PM orangutan wrote:

Hi all,

Thanks for the comments everyone. Much appreciated. Couple more questions:

1)Where on PS are the list of sellers who provide optical intensity listed?


There isn't such a list, that I know of. As Mdx said, the technology is heavily debated in the industry as a whole. Good Old Gold and SuperbCert are the only 2 Vendors I know that openly display such information. I think Nice Ice performs Brilliance Scope testing and will provide it upon request. Someone mentioned that Diamond Brokers of Florida may use Brilliance Scope. I don't know, but you might check them out as well. There's only 1 Appraiser I know of that uses the Brilliance Scope.


2)On the Brilliance Scope, what does white light, colored light and scintillation represent. Isn't most everyday light going to be white light?----------------

Rhino commented recently on a particular Brilliance Scope report explaining what each pic represented in the stone's performance. Here's a link to that thread:


https://www.pricescope.com/community/threads/b-scope-results-help.12785/