Jun 012014
 

A cross-post from The Regency Redingote:

Most people today are familiar with modern diamonds which have been cut with great precision, giving them the mathematically exact facet size and number which allows them to reflect and refract light for optimum brilliance or fire. These precise cutting techniques were first discovered and introduced into the diamond industry in the early twentieth century. Yet I have read any number of Regency novels in which the heroine or some other character has acquired a diamond which by description is clearly a diamond of a modern cut, a diamond which could not possibly have existed during the Regency. In fact, all of the diamonds which were available during the Regency would appear rather dull when compared to diamonds cut after the early 1920s.

And now, how the diamond intensified its sparkle across the centuries …

Until the eighteenth century, all of the world’s diamonds came from India and only a trickle made it to Europe through the Middle Ages. In the ancient world, the diamond was valued for its hardness, not its sparkle. Most diamonds found in the rough tended to be octahedral in shape. These extremely hard crystal octahedrons were only lightly polished, using diamond dust, just enough to polish away any surface flaws. Even that effort took a very long time with primitive tools, so that quite often diamonds without egregious surface flaws were simply set in their rough state. There were several reasons for this practice.

In India, in particular, diamonds and other precious gemstones were valued for their size, much more than for their brilliance. Because of their hardness, Indians believed diamonds to be powerful talismans against bad luck and danger, thus the larger the better. And across Europe, even into the years of the Regency, gemstones, particularly diamonds, were valued as much, if not more, for their symbolic and amuletic value, rather than their sparkle. However, the Europeans did enjoy the sparkle of diamonds enough to sacrifice some of their size to cutting which would enhance their glitter. Diamonds were so rare in Europe during the Middle Ages, that, just as in India, only kings typically wore them. And these kings employed diamond cutters to improve the appearance of their precious diamonds.

The first diamond cut was the point-cut, which was simply a naturally occuring octahedral diamond crystal which had been polished by a mixture of diamond dust and olive oil. This cut looked like two pyramids joined together at the base. It was the profile of this shape which was adopted as the diamond shape on playing cards. The polished diamond would be set into a ring with gold bezel which came up around the diamond so only the tip of one side of the octahedron was visible, similar to those illustrated at Vaka Design. This was the only type of cut and polished diamond known in the Middle Ages and continued to be the most common into the Renaissance. During that time diamonds were typically worn only by men, usually monarchs. Diamonds were so rare that they were seldom if ever worn by women. By the reign of Elizabeth I, high ranking women were allowed to wear diamonds. Queen Elizabeth is known to have worn a point-cut diamond set in a ring, which she, like many of her courtiers, sometimes used to cut love messages into glass window panes.

The next diamond cut was known as the table-cut, in which a little over a third of the upper point of the diamond was cut away, leaving a flat surface, or table, surrounded by four rectangular facets, leaving the lower point untouched. But just as with the point-cut diamond, the table-cut diamond was also set into a ring or other jewelery surrounded by gold or silver. Thus, even the little light it might reflect was blocked, making these old diamonds appear dark, almost black. This dark dullness is one of the reasons that diamonds were not the most popular gems for several centuries, seldom preferred to colored gemstones.

By the end of the sixteenth century, a third diamond cut was introduced. Known as the eight-eight cut or the single cut, four more facets were cut at the corners of the four rectangular facets of the table-cut, creating eight facets below the table. Sometimes narrow facets were cut at the corners, but more often these four new facets were cut widely enough that all eight of the completed facets were approximately the same size, giving the diamond a more rounded shape. More importantly, eight facets were also added below the girdle, the protruding edge which divided the upper section from the lower section of the diamond crystal. Thus, this diamond cut had eight facets above the girdle and eight below. These additional facets allowed more light into the center of the diamond, giving it a bit more sparkle than a simple table-cut stone.

Around the middle of the seventeenth century, a new style of cutting was introduced. This was the old brilliant cut, also called the Mazarin cut, named after Cardinal Mazarin, the chief minister of France and a noted collector of diamonds. It is believed he may have suggested this new style of cutting. In the Mazarin cut, the number of facets both above and below the girdle were nearly doubled, to seventeen above and below, for a total of thirty-four facets. This additional faceting dramatically improved its refractive ability, allowing diamonds cut in this way to sparkle more than diamonds had ever done before. Following this trend, by the end of the century, the double-brilliant was developed, probably in Venice. The double-brilliant diamond cut had fifty-eight facets, which once again increase the sparkle of the diamond, releasing more of its fire than ever before. Both the brilliant and the double-brilliant diamond cuts remained popular though the nineteenth century, including during the Regency.

As early as 1500, a few of the more expert and talented European diamond cutters were already beginning to understand that the more facets a diamond had, the more it would sparkle as it was able to refract more light. Diamond cutters began to apply geometry to the cutting process in order to determine how to further develop and enhance the diamond’s brilliance. This became increasingly important as more and more diamonds flowed into Europe from India, since this increased flow of rough stones now included many which were not of the familiar octahedron shape or were of much greater size. They also discovered clever ways to use the tiny diamond chips which resulted from this additional cutting. Thus were born the rose-cut diamond and later, the rosette.

The rose-cut, a unique style of diamond cutting, is believed to have originated in the fourteenth century, probably in Holland, though it was not yet known as the rose-cut. This style was not appropriate for the cutting of the naturally occurring octahedron diamond crystals which most commonly were finished as point-cut or table-cut diamonds. Rather, it was typically employed on diamonds of irregular shape, usually large size fragments cleaved from a substantial stone. Such diamonds have a flat base, which is most often the plane of cleavage from the original stone. Initially, the crown was domed in appearance, though rather shallow, covered with triangular-shaped facets which diminish in number from the base to meet at a point at the top. The number of facets would vary with the size of the stone. During the reign of Louis XIV, people noticed that the appearance of diamonds was enhanced when they were viewed by candlelight. Diamond cutters began to experiment in order to take advance of this light effect. Soon, a new version of the cut was introduced, with a higher, more rounded dome, having more facets, which gave the finished stone the appearance of a rosebud. It was at this time that the name rose-cut was applied to this style of diamond cutting which created a diamond which glittered pleasingly in candlelight. The rose-cut remained popular into the second half of the eighteenth century, but it had fallen out of favor by the Regency. However, the Victorians, with their fascination with eclectic historical styles, widely adopted the rose-cut diamond during the reign of Queen Victoria.

Not to be confused with the rose-cut diamond is the rosette, which first appeared around the middle of the fifteenth century. The diamond rosette was created by setting tiny diamond fragments cleaved from substantial diamonds during cutting around a somewhat larger central stone. Each tiny fragment had to be carefully ground and polished to fit closely along side the others when the rosette was complete. Typically, a rosette was made up of four to nine chips around a central stone, a double rosette usually comprised twelve to twenty fragments. A single completed rosette might be mounted as a ring, but more often several of them were incorporated with larger gems into lavishly ornate items of jewelry. The rosette continued to be made and incorporated into fine jewelry right though the Regency.

In 1735, diamonds were discovered in Brazil, soon making diamonds more plentiful on the European market. The double-brilliant cut was slightly reworked at this time to create the mine-cut diamond. This diamond also had fifty-eight facets, but the crown, the section of the diamond from the table to the girdle, was slightly higher. The pavilion, the section of the diamond below the girdle, became deeper, which had the effect of reducing the brilliance of the diamond. Even so, the mine-cut brilliant was also a popular diamond style well into the nineteenth century.

Another unique, specialty diamond was also first introduced in the eighteenth century. Known as thin-cut or portrait-cut diamonds, these were actually thin, transparent slices of diamonds with tiny, irregular facets around the edge. They were placed over miniature portraits which were set into jewelry or small bibelots such as patch or snuff boxes, in order to protect the tiny paintings. The irregular faceting on the edges made it easier to secure these thin diamond slices in place.

By the Regency, the point-cut, the table-cut, the eight/eight-cut and the Mazarin cut were no longer in use. The rose-cut style was occassionally still used, but it was not considered fashionable. However, many old diamonds were still in existence which had been cut in these styles. Very often, these old-style diamonds were re-cut into newer styles, which is why so few of them exist today. Those who purchased diamonds from a Regency jeweller would be most likely to acquire mine-cut diamonds, as they were the most fashionable. However, there were still many who preferred the double-brilliant cut, and many diamonds of that style could be seen in Regency drawing rooms and ballrooms. Fancy diamonds, usually of the double-brilliant cut style, were also available by this time, including the oval, the pear and the heart. One could also have a marquise or navette-cut diamond, which was said to have been originated by Louis XV. The French king commissioned the royal jeweler to cut a diamond which would capture the beautiful shape of the mouth of his mistress, the Marquise de Pompadour.

What may be surprising to most people to today is that many diamonds in the past were backed with foil to increase their sparkle, and in some cases to add color. Yet, even with a foil backing, none of these Regency-era diamonds sparkled with the incredible fire and brilliance which can be seen in a diamond cut in a modern-day style. If placed next to a modern brilliant diamond, they would have seemed like a fire banked down for the night next to the full, raging blaze of a modern stone. Even though both the double-brilliant and the mine-cut diamonds had the same number of facets as those found in the modern brilliant cut diamond, the impediment is imprecise geometry. It was not until 1919, at the University of London, that Marcel Tolkowsky developed the precise mathematical formula for cutting diamonds for maximum brilliancy. Tolkowsky was an engineer from a family of Belgian diamond cutters, who was working on his doctoral thesis. The geometrical precision of his formula allowed a diamond to refract the greatest possible light, thus increasing its fire to the maximum level possible. This new cutting formula was adopted around the world and all of the diamonds we see today are cut using this basic formula, a formula which was not even known during the Regency.

So, the next time you read a Regency novel in which a diamond is mentioned, do not let yourself visualize the firey gems which are available today. A Regency diamond would have been less highly polished, with considerably less fire, more banked that blazing. Yet, those diamonds, especially those with a foil backing, would have sparkled softly in the candlelight, more subdued that today’s diamonds, but certainly still appealing.

To learn more about the history of diamonds:

Dickinson, Joan Younger, The Books of Diamonds: Their History and Romance from Ancient India to Modern Times. New York: Crown Publishers, Inc., 1965.

Emanuel, Harry, Diamonds and Precious Stones. London: John Camden Hotten, 1867.

Finlay, Victoria, Jewels: A Secret History. New York: Ballantine Books, 2006.

Harlow, George E., The Nature of Diamonds. Cambridge: Cambridge University Press, 1998.

Hart, Matthew, Diamond: A Journey to the Heart of an Obsession. New York: Walker Publishing Company, 2001.

Legrand, Jacques, ed. Diamonds: Myth, Magic and Reality. New York: Crown Publishers, 1980.

Milne, Jean, The Story of Diamonds. New Haven: Linnet Books, 2000.

Schumann, Walter, Gemstones of the World. New York: Sterling Publishing Company, Inc., 2009.

Streeter, Edwin W., Precious Stones and Gems: Their History, Sources and Characteristics. London: George Bell & Sons, 1898.


Voillot, Patrick, Diamonds and Precious Stones. New York: Harry N. Abrams, Inc., 1997.


© 2010 – 2014 Kathryn Kane, Kalligraph
Originally posted at The Regency Redingote
Posted at The Beau Monde by permission of the author.

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