Diamonds have been known to man as a separate gemstone for a minimum of 3000 years, and possibly longer. However, its hardness and rarity made it difficult for hundreds of years for it to be used in anything but its natural form as pulled from river gravels.
It wasn’t until the 1200’s that diamonds started to be cut using diamond dust, oil, and a steel plate. Stones could now have a more finished appearance, but still lacked brilliance, dispersion, and scintillation. Over the following 700 years, technology, optics, and trade affected diamond cutting and the cuts started to become more complex. In the early 1900’s, Marcel Tolkowsky quantified mathematically how diamonds should be cut and the proper proportions to return the maximum brilliance.
It is now commonplace for diamonds to be cut using the latest in computer-controlled, fully automated machinery. They can be graded using equipment that evaluates the perfection of cut, from “Hearts and Arrows” to the latest laser-scanners showing angles and index settings. Grading criteria have been developed that were unheard of even a few years ago. Modern cut diamonds are evaluated using these new technologies to the benefit of the modern consumer. But what of that chance encounter with a historic point cut diamond, or any of the other cuts leading up to the round brilliant? Would you be the type to evaluate it against modern criteria, dismissing it as a poorly cut stone and worthy of recutting? Or would you be able to appreciate the long-ago efforts of a cutter and his assistants, toiling over a small rotating wheel in a dimly lit workshop for years, attempting to create an object of beauty out of an extraordinary piece of river gravel? Only by understanding the evolution of the different diamond cuts, and the difficulty others had in creating these old stones, can their true beauty and real worth be realized.
The Journey Begins
The first industrial use of diamonds is recorded by the discovery of a sapphire bead accurately dated to 1000 B.C. This would have been created using a diamond drill, where two small diamonds were attached to a wooden rod probably using pitch or resin, then rotated using a string bow and pressed against the bead blank. Diamonds were first mentioned in historical texts as early as around 400 B.C., and some think much earlier. Regardless of written texts, the earliest piece of diamond jewelry that still exists is a small octahedral crystal set in a 1st Century Roman ring.
The first historical diamond deposits were located in India. Stones over 10 cts, or a perfect crystal of any size, were considered property of the local maharajah. It was rare for any diamond to make it out into the local market. Even if they did, they were small and probably smuggled, or too small for the maharajah to be concerned about. It is recorded that violators when caught were put to death by being tied to a stake and attacked by half-starved large dogs. A whole new meaning to “Unleash the hounds!”
Diamonds were obviously known to the Romans, but as a gemstone they were so rare that they couldn’t develop much of a following over most of Europe. There just wasn’t the supply to make them that well-known. Not only were they scarce, but they were so hard that they couldn’t be shaped. This gave them a mythical property of being indestructible. Imagine an individual of this time looking at a small, perfectly formed octahedral crystal, with its natural polish and therefore quite beautiful, capturing the light in a captivating way, and knowing you cannot alter its form. No wonder they were held in such high esteem!
Now, a small disclaimer. In the discussion below, various well-known historical cuts have been omitted as the emphasis is on the development of the round brilliant. Herbert Tillander describes over 200 diamond cuts used throughout the centuries, a bit too exhaustive here. So sit back and enjoy a bit of history.
The earliest European writings alluding to diamonds were inventories created in the early 1200’s. At this time, these were diamonds as found in their natural shape and placed in a setting. The art and science of diamond cutting had as yet to be developed. The material was too hard to be fashioned as there was nothing that could be used to grind, shape, and polish it.
Somewhere between 1280 and 1310 inventories showed diamonds that were “made”, or altered from their original crystal form, as opposed to “unmade” stones in their natural state. This indicates that someone finally figured out that the only way to grind a diamond was with diamond. These early stones were primarily fashioned from crystal octahedrons, resulting in the point cut. These “made” stones mimicked the octahedral shape, as it took advantage of the decreasing softness as the grinding angle deviated away from the hardest surfaces (the crystal faces). These planes lie at an angle of 54.74° from the base of the pyramid in an octahedron. These early point cuts had angles ranging from 45 – 60°. Changing the octahedral angles slightly required the least amount of time and effort, so this was the first identified cut to be used for jewelry.
Around the mid-1300’s, the table cut appeared. This was a point cut but with one of the pyramid points ground away. This also allowed more light to enter the stone, so these were more brilliant than point cut stones. However, both the table and point cuts had pavilions far too deep to take advantage of diamond’s optical properties. Even with a pseudo-table facet, table cut stones still appeared quite dark.
There are also table cuts that have a bit of the opposite point ground opposite the table facet resulting in a small culet facet. This may have originally occurred if a damaged octahedron was purchased and the point had to be ground to remove the flaw. There are two schools of thought concerning the purpose of the culet facet. The first is that it forms a dark spot in the center of the stone, giving the eye something to focus on so that the surrounding brilliance could be better admired. The second purpose is that it acts as a mirror, capturing some of the stray light rays that would normally escape and reflecting them back to the eye for increased brilliance.
One thing that must be remembered is that there was no mechanized equipment as we know it to grind down diamonds. Some writings allude to cutters rubbing a rough diamond on a hard piece of wood with diamond as the abrasive. Slightly later writings describe a rotating metal wheel powered by a foot treadle. Either way, it is not hard to imagine the amount of labor and time required to place a small culet facet, let alone a large table facet, on an octahedron using these tools. A gem-cutter is hand-holding the rough over a wheel powered by a treadle, with an assistant dribbling oil on it to make the grit adhere to the wheel, and another assistant applying the diamond dust. Just to get the grit for grinding one would have to find non-gem diamond, grind it to dust, then sift and sort it. Then and only then could it be applied to the wheel. It’s no wonder that only royalty possessed diamonds, as the hidden costs of production were far out of reach of the commoner.
Diamonds were slowly making their way to Europe over land via northern trade routes or via the Indian Ocean and Mediterranean Sea once diamond cutting was discovered. Venice became a diamond trading center in the 1300’s as did Lisbon. These two locations parsed out diamonds to the rest of Europe with one of the earliest cutting centers starting in Antwerp. A guild of diamond cutters was also formed in Nürnberg, Germany in 1375.
The single cut was developed in the late 1300’s. This cut added more facets along the sides to improve light return, although stones were still dark due to the high pavilion angles.
It is apparent from the cuts so far that cutters were beginning to discover that diamond had optical properties that could be harnessed to turn a piece of river gravel into a noteworthy gem. There was no true understanding of the properties of light yet, but by the evolution of cuts and trial and error, it is apparent they were becoming aware of brilliance and scintillation. It must be remembered that the science of optics hadn’t been invented yet, and wouldn’t for another four hundred years, but the cutter’s interest in bringing out the maximum beauty of a piece of rough could have had a significant impact in understanding the concept of light and how to use it.
The development of the pendoloque cut was developed in the early 1400’s. This was a rather flat, pear-shaped cut used for unusually shaped, thin rough. It was not brilliant due to its flatness. However, the concept of symmetry became more important, as was the technology to create it.
The rose cut was developed in the latter part of the 1400’s, certainly no later than the early 1500’s. It has primarily triangular-shaped facets. If the back side was flat, it was considered a single cut rose. If the top and bottom were both cut and facetted, then it was a double cut rose. Stretching out a double cut rose resulted in a briolette.
Diamonds became more well-known in Europe when the Portugese conquered the port of Goa in 1510 and established a trading center. More formal commercial traffic was implemented, and diamonds became more available to European cutters. This is apparent by historical paintings of this period. Whereas paintings of royals from the 1400’s showed at most 2-3 diamonds, paintings of the 1500’s show royal clothing literally bedecked with diamonds on the bodice, sleeves, and lapels.
As can be seen, cuts were becoming more complex as the nature of light and optical properties were being explored. The Mazarin and Peruzzi cuts (not really specific cuts but more styles) were developed by the early 1600’s, with 17 and 33 crown facets respectively. This additional complexity resulted in an increase in brilliance and scintillation. The process of bruting hadn’t been developed yet, so stones were still primarily of the square/octagonal outlines, sometimes with rounded corners.
The old mine cut was developed in the early 18th century and is considered the first of the brilliant cuts. It is characterized by a high crown, a large table, and a large culet facet.
At last, the bruting machine was developed, and circular diamonds could now be created far more easily. The old european cut was developed, characterized by a tall crown, small table, and tall pavilion. This was the beginning of the true brilliant cut, as it possessed 58 facets and was circular. However, due to the steep crown and pavilion angles, brilliance, dispersion, and scintillation still suffered.
The invention of the light bulb in 1879 radically changed how diamonds appeared. Prior to this, diamonds were generally owned by the wealthy and worn in posh surroundings generally lit by candlelight. Hundreds of candles could illuminate a single room with softly flickering flames with a spectrum very heavy in the reds. With the lightbulb, this light is replaced by a single point of light, absolutely steady, with an entirely different spectrum. Diamonds now appeared far more dull. Diamond cuts had to change.
Henry Morse had quantified the American cut in the late 1800’s, and his angles and proportions were used by Tiffany and other high-end jewelers. Diamond cutting was now beginning to be a more scientific process to maximize brilliance.
Marcel Tolkowsky, a legend to the art of modern diamond cutting, did an in-depth study of optics and how it related to diamonds. His work, Diamond Design, A Study of the Reflection and Refraction of Light in a Diamond, was published in 1919 and has been considered by some to be the definitive work on the art and science of diamond cutting. It spelled out the scientific logic for the brilliant cut as we know it today. However, it was different from the American cut by only a fraction of a degree in pavilion and crown angles. In fact, a GemRay analysis shows the American cut to return about 3% more brilliance than the brilliant cut. Although Tolkowsky is given credit for the development of the brilliant cut, Morse actually beat him to it by several decades. This oversight is due to the lack of communication between Europe and American cutters at this time, plus the industry assuming that Europeans, the ones that developed diamond cutting in the first place, had more knowledge and therefore more expertise in the art.
The 20th Century ended with the process of mining, grading, evaluating, and cutting diamonds all becoming mechanized and computer controlled. There is very little reason for a human to actually touch a diamond. As a result, the romance is disappearing of a diamond cutter struggling to make an existence by spending years cutting a single stone. The Old World has had to yield to the Computer Age. A diamond may be forever, but romancing the stone is now gone.