Came upon this while researching - can anyone comment?
Any diamond proportioned between the following parameters will have, to the naked eye, exactly the same light refractive properties to one another:
Table diameter: 53 to 61%
Crown height : 11 to 16
Pavillion depth: 43 to 44.5%
The so called 'Ideal' cut and 'H&A' have these approximate proportions:
Table diameter: 53 to 56%
Crown height: 15 to 16%
Pavillion depth: 43.5 to 44
They show no advantages as to what 'sparkle', 'fire', 'brilliance',or scintillation is concerned if compared to stones with a different set of proportions.
The main difference between the two will be in the size of the diamond, as an example a 1.03ct diamond cut to very stringent parameters, as those of the 'super ideal' or 'H&A' will look around 20% smaller than another 1.03ct
stone cut to less stringent parameters. Also since more expensive diamond weight will have needed to be removed in order to cut to these more stringent parameters the end price will be more expensive as well.
Also there are increased high labour costs.
You may now ask me, why then did we decide to cut these stones?
Well the answer is we didn't, we were forced to my market conditions emanating from Japan some 13 years ago now when some dealers, in order to control the very lucrative Jap market decided first to invent the 'excellent cut' then
the 'ideal' cut a transition to the 'super ideal' leading to the phenomena of the 'H & A' effect as seen through a simple polaroid filter, similar to the sun glass lenses of the same name.
All this was built up, through advertising and slick marketing in order that the public believe that this type of cut is best.
You may now ask, but anyone could cut their diamonds to these very high specifications and compete, well again the answer is no. It needed a very high degree of cutting expertise to cut these stones and this is where we came in those 15 odd years ago.
Indeed we were approached by a top Japanese wholesale dealer who entered an exclusive manufacturing partnership with us in order to get these very exclusive diamonds.
For years we had a near monopoly on their manufacture and the world's biggest workforce exclusively cutting to these high parameters so we know what we are talking about.
Any diamond proportioned between the following parameters will have, to the naked eye, exactly the same light refractive properties to one another:
Table diameter: 53 to 61%
Crown height : 11 to 16
Pavillion depth: 43 to 44.5%
The so called 'Ideal' cut and 'H&A' have these approximate proportions:
Table diameter: 53 to 56%
Crown height: 15 to 16%
Pavillion depth: 43.5 to 44
They show no advantages as to what 'sparkle', 'fire', 'brilliance',or scintillation is concerned if compared to stones with a different set of proportions.
The main difference between the two will be in the size of the diamond, as an example a 1.03ct diamond cut to very stringent parameters, as those of the 'super ideal' or 'H&A' will look around 20% smaller than another 1.03ct
stone cut to less stringent parameters. Also since more expensive diamond weight will have needed to be removed in order to cut to these more stringent parameters the end price will be more expensive as well.
Also there are increased high labour costs.
You may now ask me, why then did we decide to cut these stones?
Well the answer is we didn't, we were forced to my market conditions emanating from Japan some 13 years ago now when some dealers, in order to control the very lucrative Jap market decided first to invent the 'excellent cut' then
the 'ideal' cut a transition to the 'super ideal' leading to the phenomena of the 'H & A' effect as seen through a simple polaroid filter, similar to the sun glass lenses of the same name.
All this was built up, through advertising and slick marketing in order that the public believe that this type of cut is best.
You may now ask, but anyone could cut their diamonds to these very high specifications and compete, well again the answer is no. It needed a very high degree of cutting expertise to cut these stones and this is where we came in those 15 odd years ago.
Indeed we were approached by a top Japanese wholesale dealer who entered an exclusive manufacturing partnership with us in order to get these very exclusive diamonds.
For years we had a near monopoly on their manufacture and the world's biggest workforce exclusively cutting to these high parameters so we know what we are talking about.
... here is an example of an H&A diamond that we passed up recently. It's H&A pattern was crisp but note in the attached file (in the simulated FireScope image) the absence of the dark red under the table (whereas the last example had dark red under the table). That lighter area indicates leakage, which indeed this diamond did have that leakage under the table and turned out to be a reject here. Not that this is an ugly stone and by no means is it. It would blow away the first 2 examples I gave above. Thing is, I have access to more of these kinds of stones and it's very easy for me to sign for them. When I'm purchasing for stock and laying out the $$$ I only do so on the rarest cut qualities.
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