Mogul Cut Diamond – Reviving the Mountain of Light!

Mar 23, 2021

The Mogul Cut Diamond (also known as Mughal) is one of the most ancient diamond faceting techniques. It is a direct alteration from the more popular rose cut (style) as we know, but with taking material mass and form as primary consideration.

One of the most famous & historically important diamond cut in “Mogul” (Mughal) style is the Koh-i-Noor diamond, in Ancient Persian, Koh-i-Noor translates to “Mountain of Light”. Some literature presents the history of this diamond dating back to the early 1300’s. The history of this diamond is so anfractuous, the interest it has sparked caused many historical debates which some are very valid, some less, to this day!

The sad part of the Koh-i-Noor lies in the fact that except for maybe a handful of historical sketches and “perhaps” a few unclear photographs, no living being really knows what it looked like. In 1852 the British Crown decided to recut it into a shallow oval formed early brilliant (Old Mine Cut) and with this its centuries long history ground to diamond dust! Its reformed version is currently residing in the Tower of London, as the centerpiece of the Queen Mother 1937 coronation crown.

Koh-i-Noor diamond

Koh-i-Noor diamond sketch – Tennant, 1852

The path to Mogul Cut Diamonds

As I mention in my earlier article “Diamond Facets – The Windows to Light”, early faceting techniques originated somewhere around the 14th century. Symmetrical rough octahedral formed diamonds would have one of their tips ground off to create the table cut, but what would cutters do with asymmetrical rough diamond forms?

Early cutters would grind and attempt polishing randomly placed facets just to bring the malformed rough into some visual esthetics, at the same time expose some optical light movements within the diamonds and allow a view of their internal water (transparency).

Such ancient diamond cuts survived only a short time as early cut evolution made them prime candidates for further cut experimentations. Fortunately we have historical books which display ancient sketches as confirmation! Such cuts are so non existent they never even earned their own nomenclature. I was lucky enough to be offered such a diamond (fig 1) many years ago from a (non-jeweler) antique merchant in the Kapalıçarşı (Istanbul Grand Bazar).

When I laid my eyes on this diamond, I knew right away what I was holding and knew that I wanted to own it. I spent a few lovely hours over lunch with the merchant and finalized a deal. Unfortunately that was many years ago before the photographic hype and I only have one picture of this diamond.

my orange antique diamond

Fig 1 – Ancient Diamond from the Istanbul Grand Bazar

Another famous diamond which originated in this early form and cut was the original discovery of a diamond mentioned in “Travels in India” by Jean-Baptiste Tavernier (1676) and described by words and a sketch “La Diamond cleane of a fair violet:” (fig 2 – Plate III ~ stone A). This ancient diamond which weighed 112 carats was sold by Tavernier together with all the others described on Plate III to Louis XIV the King of France.

Tavernier plate

Fig 2 – Tavernier’s drawings, Plate III, Stone A

Today known as the Tavernier Blue, the 112 carat blue diamond was eventually cut to the 68 carat French Blue which ultimately transformed into the 45.52 carat Blue Hope Diamond that we know today and which is on permanent display at the Smithsonian Institute in Washington D.C.

I am aware this is a rather long pre explanation about early diamond cuts, but I think it’s important to understand as they are rarely mentioned before moving on to Mogul Cuts which is the subject of this article. It’s a natural chain of events.

After discovering cutting and faceting abilities, the natural advancement would be to attempt to organize facet placements, this brings us to what most of us know as the rose cut style. (fig 3)
Rose cut diamonds are considered one of the most ancient techniques for cutting rough diamonds into some sort of symmetrical faceting configuration.

Naturally rose cuts are better defined in the more popular small and flat versions, but for large, thick and out of form rough diamonds, cutters were required to develop a new skill. It entailed physically designing their way into an esthetic and appealing facet placement configuration. An extremely complicated task on the hardest substance…, especially back in history.

The birth of the Mogul Cut Diamond, May I add, a well earned and worthy name!

Rose cut Diamond

Fig 3 – Antique Rose Cut Diamond (cleaned)

Mogul Cut Diamonds – Rose Cuts on Steroids

Mogul Cut diamonds are in plain language rose cuts on steroids…, when rough diamonds are small and flat, it would make economic and practical sense for cutters to pre-balance (block) rough diamond into various forms & shapes. This permitted a higher symmetry division and more uniformed faceting on rose cuts.

Antique rose cut designs consisted mostly of triangular facet arrangements covering the domed surface side, rose cuts don’t possess a pavilion, instead they have a singular flat facet (base) on the opposing side of the dome. (see fig 3)

Now let’s change the subject to large, thick and out-of-form rough diamonds, preserving their weights was of primary objective and required cutters to re-invent themselves on each and every diamond they were cutting.

Any three dimensional symmetry requires a balanced base/form to begin with, the more out-of-balance, the more physically complicated to cut and place facets at any sort of symmetry arrangement or order.

Mogul Cut diamonds always intrigued me, twenty some years ago when I started to reinterpret antique & period diamond cuts, Mogul Cut diamonds were and still are just a vague subject. Since then not much information about them was published, almost no imagery to be found, just a few historic sketches and perhaps a few unclear photographs (fig 4) you can count on one palm. To me, Mogul diamonds were just a mirage waiting to be materialized.

Iranian Mughal diamonds

Fig 4 – Iranian Mogul Diamonds, Case 24, No 36, V.B. Meen, 1968

Materializing an Old Dream

I always had a dream to find a suitable rough diamond which would allow me to practically rediscover ancient techniques cutters utilized almost a half a millennium ago. I believe understanding what went through such a cutter’s mind would enhance my knowledge for historic cuts and their effectiveness. Needed to start with a large specimen, a very pricy experiment.

Lab Grown Diamonds (LGD) opened such a possibility for me, I just had to wait for some technological advancements such as growth, water (transparency) quality and size availability. I found the perfect diamond growing facility right here at home, Israel.

A few months ago I connected with Lusix, an Israeli diamond growing facility, part of the world renowned Landa group, a multi-disciplinary group of companies with a wide range of R&D services which growing diamond technology is just one.

My first initial tryout on Lusix LGD’s was fully documented on my previous article blog which you are welcome to read and understand my take on them (tip: it’s by no means conventional). I was very impressed by their diamond growth structures and water (transparency) quality, their R&D determination to the cause, I have decided to endorse their LGD material as a base for my man made diamond designs and offerings.

A full Israeli integrated offering, Lab Grown Diamond cuts & designs made 100% in Israel. From their exclusive growing capabilities to the designing, planning and finally the cutting & polishing into a finished gem, all created and controlled in house here in Israel.

One of the recent *LGD’s I have selected, sparked a Mogul Cut diamond design in my mind, finally I had the chance to materialize a twenty year old dream. I chose to jump the waters, go back in history several centuries and enter the minds of the ones who were exploring the first diamond cuts.

* This Mogul Cut Diamond was crafted out of a Lusix created lab grown diamond and possesses the unique Type IIa purity which are ironically so coveted in the antique diamond world.

Reviving the Mogul Diamond Design

So here I am holding this newly grown diamond (fig 5), and just as a half a millennium ago, the diamond’s form & structure is leading me directly into my new journey. Firstly, I needed to cut out some of the external surface irregularities which determined the base-form I had to work on. I then began the pre-forming process by adding one facet at a time randomly onto the LGD body.

lab grown diamond before cutting to mogul cut

Fig 5 – My selected Lusix LGD before cutting

This I quickly found out is a tricky task, the more unorganized the facet placements, the more complicated the way forward. I needed to find a base to work from. I began subdividing my facet placements based on symmetrical folds, first 4 fold, then 8 fold and so on…, ironically the end design consisted of an uneven fold division, confirming its complexity.

This procedure needs to progress delicately because I didn’t want to excessively cut into the diamond which will grind away too much weight and form. It’s kind of… “you know where you start but you have no idea how you finish” type of a process.

Right on the start, I hit a bump on the road, just like in natural diamonds, LGD’s also have plans on their own sometimes, as we are covering the diamond with preliminary facets, one of the surface irregularities expanded into a rather large feather extending almost from top to bottom on its height, luckily the feather expanded by the edge of the diamond form. (fig 6)

cutting lab grown diamond to mogul cut bumping a feather

Fig 6 – Cutting process phase 1 – expanding feather

I live by the phrase “from everything bad comes something good” and immediately noticed an opportunity born out of this unfortunate occurrence. Since I am attempting to enter the historic cutter’s minds, I chose to tackle the feather with their state of mind moving forward.

Eliminating or cutting through the feather entailed the skewing of the rough form on the feathered side solely. A primitive fashion that doesn’t hold water today which would require a completely new planning process. I chose to move forward the old fashioned way.

As this journey unfolds, we will learn my choice was the right way forward, not only did it allow me to enter the cutter’s mind, it also educated me tremendously by further complicating my path to discovery. That feather incident became a crucial part and highlighted the old charm of the finished Mogul LGD. (fig 6b)

Yellow line displays how the internal feather determined the final shape

Fig 6B – Yellow line displays how the internal feather determined the final shape

Re-discovering the Mountain of Light

As mentioned previously, there are no Mogul diamonds to be found less alone physically study.
In our eyes and minds, similar antique cuts that survived like the rose or briolette cuts don’t reflect lights from within the diamonds, such offer a shimmering light show usually originating from light reflections as light hits the external facets flashing and mirroring white lights back for a different optical enjoyment.

The famous Koh-i-Noor diamond was just one gem (albeit one of the most important) from what literature reads as an ocean of jewels & gems looted from the treasury of the Mughal Empire when Persia’s Nadir Shah sacked Delhi in 1739. It further claims that it was Nadir Shah himself who exclaimed “Koh-i-Noor” when he first saw the diamond. I always thought to myself, what did he see that initiated the Persian words “Mountain of light” as a first reaction.

Here is where it starts getting interesting…

For those of you familiar with my writing, it wouldn’t be surprising that I love to research my work constantly. This rare opportunity to reincarnate a real lost and forgotten cut allowed me to practice my knowledge and discover a play-of-light configuration which might have been lost in history, but did our forefathers know? I am starting to believe they did.

The first preliminary faceting contouring the rough form did not display what was about to be revealed…, the diamond started looking more like a type of briolette being born, the facets allowed a wonderful & clear view into the LGD water or transparency, with some external facet shimmering as the diamond moved. (see video 1)

Video 1 – external shimmering, internal water view, (bonus: feather minimizing)

As I continued subdividing the contour by cutting additional facets I started noticing small but confirmed optical light reflections from within the diamond…, surprise!! As I subdivided facets further, more optical occurrences started to appear. I began to follow the lights. (See both fig 7 and video 2)

cutting lab grwon diamond to mogul cut phase 2

Fig 7 – identifying a genuine spectral occurrence

Video 2 – spectral events & internal reflections noticeable as the diamond moves

This did not deter me from my initial plan, to replicate a Mogul Diamond as realistically as I possibly could. Even though I did discover the light within, my focus remained to continue and deconstruct the Mogul’s faceting logic behind their multifarious faceting designs.

As mentioned above, cutting and placing facets at any kind of symmetry on an off-balanced topography is a very complicated task. Finding a method to keep facet junctions (the line that separates two facets) in any kind of continuant line is like finding your way in complete darkness. Every surface bump or trench steers your facet junctions in other directions/angles and you end up with a symmetrical mess, both aesthetically and visually.

We needed to learn to steer facets and their placements into some sort of symmetrical flow. This meant balancing each single facet separately at an angle complementary to its subsequent facet while planning its succeeding facet and position, time & time again. I suppose back then, when time was not necessarily a luxury, such intensive crafts were still a norm.

Some surface irregularities located at the base (widest part) of the diamond needed separate faceting considerations, such would influence physical diameter size and weight too much if cut to the flowing symmetry of the upper portion facets.

The base contour would require a different set of facets which needed to eventually blend in with the overall symmetry flow. A crucial art, very complicated to achieve with any kind of continuous flow.

As we were moving forward adding facets covering every raw patch on the diamond, the light intensity within the diamond kept escalating. I don’t really know if our readers can physically relate, actually I don’t know of anyone at this point of time who can because honestly, there are no such cuts to be found less alone study or research.

This was the moment when I realized why Nadir Shah exclaimed “mountain of light” upon putting his sight on the Koh-i-Noor. In some sort of humble comparisons, my little Lab Grown Diamond began to glow, and that is when I am only half way through its discovery – (see video 2)

As can be noticed in the above video and picture, the diamond is already fully covered with partially organized faceting. Now it was time to really enter the historic cutter’s mind. This would steer us in the right direction locating the paths to better align the facets. Moving from facet to facet repetitively until the facet junctions followed a symmetrical flow. (See video 3)

Video 3 – Starting to take shape with a faceting symmetry flow

Amplifying the Lights Within

At this stage we were just about half way down our enthralling journey, what I called preliminary faceting shifted to the diamond being blocked (in generic cuts, what we call 8×8, e.g. 8 crown & pavilion facets in place), in our present case, a multifold of facets.

The next stage is where the craftsman’s prodigy gets noticed. We know that generally after the initial blocking of diamonds, the next stage is the brillianteering of the diamond facets. This is the stage when cutters go on to subdivide the blocked facets further into smaller symmetrical facet shapes like the triangular star, lower & upper girdle facets (also known as half facets).

On generic cuts this stage has become crucial but quite methodical, but how on earth can you perform such a brillianteering procedure on an off-balanced topographic diamond form in the first place?

I quickly learned that a huge challenge was simply discovering ways to securely hold the diamond in its tang. Since the Mogul Cut’s structure is completely different from modern cuts, it would require different faceting slopes than your usual diamond cuts. We were required to develop adaptation aids to our dops and tangs (holding tools) in order to allow us to securely reach the Mogul Cut’s unique facet angles.

Next came a physical trial to subdivide a few facets to an exact replication that we see on the Koh-i-Noor’s historic sketches (fig 8). An extremely delicate procedure that requires steady hands but more importantly a relaxing state of mind.., this is all new to any modern day cutter and the angle variants between adjoining facets are so amorphous that any wrong move will throw you off-plan and require a new attempted repetition.

Koh-i-Noor diamond brilanteering

Fig 8 – Koh-i-Noor diamond sketch, triangular brillanteering facets encircled

After numerous tryouts and a lot of historic cut logic, we managed to figure out a methodology to replicate and move forward. (fig 9) The function for further subdividing the existing facets is to split light upon entry and exiting the diamond, and to pluralize and minimize external facet flashes as can be clearly noticed in video 4.

Mogul diamond brillianteering

Fig 9 – Mogul Cut brillianteering attempt (encircled)

Video 4 – Triangular facets are changing the external light reflection dynamics

Discovering the methodology of this ancient faceting technique was crucial, each and every facet required slightly different polishing measures in order to align facet junctions and connect their meeting points in its unique symmetrical flow.

As we got closer to the base of the diamond, substantially more effort & intellect was required to naturally mend the off-balance topography surface into the existing symmetrical flow. At this point and stage, a Mogul Cut statuette was to be noticed already. (fig 10 & 11)

Sarin sketch vs real diamond

Fig 10 – Sarine 3D model vs. real model (4 facets outlined in red)

Sarine 3D model vs. historic Koh-i-Noor sketch

Fig 11 – Sarine 3D model vs. historic Koh-i-Noor sketch

It took effort, time and plenty of patience to delicately cover the whole contour of the Mogul form to such an ancient faceting pattern, when we finally completed, I understood right away the unfortunate ceasing and the lost potential that laid in further exploring and innovating this wonderful ancient diamond cut design.

The only thing left to do was to more accurately rectify the bold and out-of-symmetry facets contouring the base allowing a unique symmetrical flow with the overall symmetry. This again demanded a different approach to each and every facet contouring the base. (see fig 12)

Ancient symmetry rectification

Fig 12 – Ancient symmetry rectifications (outlined in red)

The Rebirth of the Mogul Cut Diamond – 2021

After a full fifteen day journey, I can finally claim I was able to reincarnate the lost art of cutting a diamond to an historic Mogul faceting style. Stepping in the footsteps of ancient cutters was crucial to understand the roots which brought this wonderful ancient cut to life. And the results…, as usual, I will let my readers be the judge of this work! Hope you enjoy the high definition video at the end of this article.

This Mogul Cut version was executed to a 19 fold symmetry (e.g. 19 different vertical faceting divisions) which include no less than 96 facets covering the whole diamond, including base & table (excluding 20 minor facets). According to a research conducted for GIA’s Gems & Gemology, summer 2008 on the plaster model of the original (pre-cut) Koh-i-Noor, their findings numbered the original facet count at 169.

There is no doubt their size differences required a whole different symmetry fold and facet amount but as the executor of this new Mogul Cut specimen, I must admit the resemblance between the two puts a smile on my face! (see fig 13) 

Mughal vs Koh i Nur_wireframe

Fig 13 – Comparing forms & faceting between GemConcepts Mogul Cut and the Koh-i-Noor


Twenty years ago when I had the aspiration to recreate this lost ancient diamond cut I really had no idea of its potential appearance. Like most, I always thought that at the end of the day, it would appear similar in nature or close to what rose and briolette cuts offer as far as play of lights. Boy, was I wrong!!

Lab Grown Diamonds allowed me the creative freedom to bring this old aspiration into reality. About a third way into my journey I chose to confirm my early findings that a genuine optical phenomenon was actually occurring. A three dimensional scan-file of the preliminary cut and form was translated into an Octonus based application which further supported my findings.

Playing a virtual movie of the diamond movements in an AGS ASET (Angular Spectrum Evaluation Tool) lighting environment confirmed genuine total internal reflection back to the viewer. (see video 5) A short explanation of the colors we notice in the virtual video.., RED = direct light return – GREEN = indirect light return – BLUE = contrast/obscurations and grey/white = leakage. More about this subject in our blog “Diamond Angles, paragraph 4”.

Video 5 – Virtual ASET video reflecting the diamond’s play of light

For well over a century, industry professionals have been designing and cutting diamonds to a bipartite structure configuration. In order to create brilliance, colored fire & scintillation a diamond required firstly a pavilion section and preferably a related crown section.

This journey of mine is a live testament to the fact that lapidarist living 400 – 500 years ago knew something most of us presently don’t because such type of diamond structure was never further explored.

Angle of incident…There are different structures that can potentially bring diamonds to life and enact a plurality of light shows…, all that is left to do is to further research, develop and innovate new potential diamond statuettes! Who said a diamond needs to be round?

In order to give potential diamond designers & cutters some thinking material going forward (am I too hopeful?), I am adding this sequence of four photo’s each revealing the diamond’s potential optical wonders and their raison d’etre!! (fig 14) The big secret of this cut lays in its multifunctionality, from whichever position it is looked upon, the Mogul Cut’s play-of-lights will not disappoint! 

A sequence displaying diamond optical properties, brilliance, fire and the virtual facet patterns responsible

Fig 14 – A sequence displaying diamond optical properties, brilliance, fire and the virtual facet patterns responsible

And as I conclude lately…, to be continued soon enough.

Disclaimer: I was not familiar with the GIA Gems & Gemology, Summer 2008 published research and modeling of the Koh-i-Noor diamond until the writing of this article which began after the completion of our Mogul Cut LGD. I did read it with great interest but at the end of the day chose to share two small excerpts which definitely made my day. (see fig 15)

Excerpts selected from Gems & Gemology, Summer 2008 on the Koh-i-Noor Diamond

Fig 15 – Excerpts selected from Gems & Gemology, Summer 2008 on the Koh-i-Noor Diamond

PS.. I always believed diamonds should not be limited to the shapes and cuts of current norms but should be further explored…, I keep envisioning little statuettes designed and cut to play the lights, I guess we needed to go back a half a millennia to discover its been already done but lost & forgotten…, hoping this article sparks up a potential.

Thank you for reading, Y

High Quality Video

We suggest to set video to HD and watch in full screen

Wondering what Mogul cut diamonds looked like hundreds of years ago? Introducing the Mountain of light ~ 2021

Mogul Cut Diamonds – FAQ

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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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