Three Dimensional Optical Symmetry – The Naked Truth

Feb 28, 2022



In my last article “Diamond Cutting Philosophy Painted in Colors”, I touched upon a new philosophy, a unique insight into diamond cutting uncharted waters for many, if not most. (I am not aware of anyone implementing such techniques).

A different methodic which makes diamond cutting more interesting, intriguing and Fun! A new avenue which opens opportunities for genuine innovation but more importantly it enriches our intellect and frees us from the old ways and habits.

We must admit the old ways are trapping us in the 20th century and metaphorically holding our industry hostage! Diamond cutting can be much more than a manual laboring profession.

It is true.., there were some nice advancements since the 1980’s when H&A round brilliants started appearing but ironically not much has evolved since except fine-tuning the standardization of the round brilliant cut.

As for fancy shapes and cuts it’s been even more of a calamity, not much has happened design wise except for exhausting the old/new terms of excellent symmetry & polish which we all (should) know don’t really mean much in regards to a diamond’s play of lights let alone its beauty potential.

Technologies and the Tools

In our preceding article, I discussed high-level 3D optical symmetry precision and how current 3D scanning technologies offer erred information by default simply due to their admitting and systemic margins of error.

2 Subsequent 3D scans displaying pavilion numbers of 1 round brilliant diamond

Figure 1 – 2 Subsequent 3D scans displaying pavilion numbers of 1 round brilliant diamond

Technological tools, at large were and somehow still are modified to primarily accommodate mainstream manufacturing capabilities within their standard requirements (the norm). I claim their limitations are also partly responsible for stalling further innovation.

This causes millions of cutters across the globe from further exploring and with the help of major gemological laboratories developed a modus operandi which keeps craftsmanship in the box instead of encouraging explorations outside the box.

Currently, if cutters reach and position themselves within the “excellent-cut” scope allowances, they have reached what is presently considered the pinnacle diamond cutting when achieving grades such as triple X (triple excellent) and/or Ideal 000 by major independent laboratories such as GIA or AGSL. (both considered highly regarded for their cut grading schemes)

In case cutters do choose to explore further they are quite limited by the technological information they currently have to work with and moving forward to novel designs or higher levels of optical precision forces them to work and think out of these limitations.

Bursting Through Walls of Limitations

During my years of diamond design I have explored with most aiding tools, from designing and implementing completely manually (pre-technological era) to utilizing the latest high tech availability.

With the years I slowly learned to rectify manual practice with high technology but no doubt my intellect on diamond design grew physically with the old fashioned cleaving tools, tangs, and plain cutting wheels while depending on old measuring devices like this Moe Gauge (see fig 2), I guess I can comfortably claim the genuine roots of diamond design!

The moe diamond weight gauge

Figure 2 – The Moe Gauge – widely used until the 1990’s – ironically still used today

Today I try to utilize technology to mostly optimize my processes because even presently most technological tools are still intended to service mainstream norms (“in the box” as mentioned above) which is lightyears away from the current me.

I will utilize current technologies relevant for my goals and processes to the highest degree but at a certain point I must release myself from their information reliance to practically move forward and control my processes until satisfactory achievement. (I know…, I know…)

This is exactly the reason I chose to demonstrate what I am trying to explain with the following pictures while introducing the only (not commercially available) error-free tool I am aware of which interprets complete and accurate information in relation to a diamond cut and lights traveling through its faceted medium.

ETAS – Effective Total Angular Size

ETAS describes the optical potential of any faceted diamond in a visual (albeit convoluted) fashion. It allows predictions of actual and forward light responses of an individual diamond cut. ETAS offers all optical information based on direct light interaction with the diamond. All that is required is learning to analyze the tremendous information it offers.

There are two different ETAS measuring options, one is virtual based on generated 3D scans which as we mentioned are slightly erred by default, and the second is manual which is based on physical interactions between faceted diamonds & light. The following images will further elaborate.

Based on our latest research manual ETAS can be used as a most reliable tool to comprehend optical symmetry information of the diamond’s three dimensional cut. After all, it displays an actual forward light mapping of each placed facet in a most detailed manner. Manual ETAS is being currently tested with no computer aids which means no margins of error!

Virtual ETAS – Octavia Cut vs. Vintage Style Asscher Cut

To demonstrate I will start with a comparison of two of our signature diamond cuts, The Octavia Diamond (the exemplar from our previous article “Diamond Cutting Philosophy Painted in Colors)” (see fig 3) and our vintage style Asscher Cut diamond (see fig 4).

Octavia Diamond - virtual image and relative ETAS

Figure 3 – Octavia Diamond – virtual image and relative ETAS

Both are square emerald step-cuts designed and crafted to great detailed attention for different efficacies. The Octavia for its 3D optical symmetry apex and the vintage Asscher Cut for exhibiting an antiquated charmed look. Both considered very fine examples in their respective craftsmanship segments.

Figure 4 – Vintage style Asscher diamond – virtual image and relative ETAS

Figure 4 – Vintage style Asscher diamond – virtual image and relative ETAS

Now let’s place both the Octavia and vintage Asscher virtual ETAS’s side by side (see fig 5).

On the left (Octavia) we are able to notice it offers denser spectral events, increased grouped uniformity and a wider spread or reach.

The Octavia diamond demonstrates superior and orderly arrangements of close similarities between the various groups of events created by the different sections (4 main & 4 corner) of the diamond.

On the right (vintage style Asscher) we are able to notice less arranged and crowded spectral events while appearing significantly larger by size when comparing to the Octavia events. One of the unique visuals created by step-cut faceting styles in general.

Similarly as with the Octavia this virtual ETAS also demonstrates the 4 main & corner sections of the diamond…, they are much less distinguishable than the well arranged optics Octavia offer.

While both diamonds were finely and carefully crafted to higher than normal symmetry levels, this comparison doesn’t leave any doubts in regards to their three dimensional optical symmetry levels of precision and craftsmanship.

Virtual ETAS comparisons between Octavia left & vintage style Asscher right

Figure 5 – Virtual ETAS comparisons between Octavia left & vintage style Asscher right

Manual vs. Virtual ETAS Explained

Since I did touch upon the slight misinformation 3D scanners offer by default (margins of error), I thought it would be a good idea to simply compare between manual (real) and virtual ETAS for our *Octavia Diamond.

Octavia Diamonds undergo a very unique planning, cutting and polishing journey, they are classified and known as square emerald cuts crafted to the highest 3D optical symmetry. Thus I found it the perfect candidate to demonstrate a realistic close-up addressing the margins of error discussed in this (and previous) article.

In figure 6, I am actually showing a comparison between a manually created, real ETAS (left) by the physical diamond and a virtual ETAS (right) generated by a Sarine Diamension 3D scan of the same exact diamond.

As is transparently displayed, real ETAS is a rather simple test, a concentrated light beam is aimed directly at the center of the diamond face-up allowing total reflections back onto a dark colored platform parallel to the diamond table. This translates light travel and reaction of each and every facet on the crown and pavilion in a three dimensional manner.

The information presented is accurate, errorless and complete (as long as the diamond face and light source are parallel to each other). We just need to be able to translate into comprehensible information. Once we are able, all the true information regarding diamond cut and its three dimensional optical symmetry will be understood much better.

*The exact same diamond subject of our previous article “Diamond Cutting Philosophy Painted in Colors”

Comparisons of a Real & virtual 3D generated model exhibiting their ETAS

Figure 6 – Comparisons of a Real & virtual 3D generated model exhibiting their ETAS

Manual vs. Virtual ETAS – the Comparisons

Firstly we need to consider the fact that manual ETAS (left) is displayed on a 2D (dark) flat platform while the virtual ETAS (right) is displayed through its 3D spherical view (the wonders of technology) which can be a bit confusing visually.

Upon closer study we are able to notice the common groupings, flash event shapes, forms and spectral colors as traveled and reflected through the diamond’s internal and external faceting. Both display an inner and outer periphery of 4 main and 4 corner sections of the square (octagonal shaped) emerald cut.

Upon closer and selective view, we can notice the manual ETAS (left) displays higher and clearer precision in both positions and relative shapes of events while the virtual ETAS (right) reflects a bit more variations between the similar mirrored events (see figure 7).

Circled - points of comparisons between manual (left) & virtual (right) ETAS

Figure 7 – Circled – comparison zones between manual (left) & virtual (right) ETAS

Overall, I must admit the virtual ETAS is a fair and accurate representation but when we choose to dive deeper and work within current technology limitations, we can understand why the manual ETAS is much preferred for true realistic information.


I am not writing this information to belittle the technological tools we currently have to work with, on the contrary, it is exactly these limitations that pushed us forward and search for the unknown.

My only hope is that sometimes in the near future, everyone will understand that staying within their comfort zone (e.g. in the box) only stalls natural evolution and the great potential diamond design has for its future.


Graphics courtesy of Octonus

About Yoram Finkelstein

About Yoram Finkelstein

Mr. Finkelstein a proud second generation Diamond cutter. In 2010 He founded GemConcepts Ltd. which specializes in designing and cutting unique Diamonds using a new approach, a new philosophy. GemConcepts design Diamonds that mix the “old world” approach with the newest cutting-edge technologies.

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