Diamond cutting has a surprisingly rich and constantly evolving history. It can be traced back to the Middle Ages, though there is still much about this period in diamonds that are unknown. It is believed that in both 6th Century India and 10th century Islam diamonds were not cut to be enjoyed as jewelry, but were ground up and used to polish other stones. The history of diamond cutting really begins in the 14th century.
Early Years – 1300’s, 1400’s and 1500’s
The first diamond cut was called the pointcut, which dates to the late 14th century. This cut followed the natural shape of the octahedral crystal. In a process called cleaving, a chisel was placed on the diamond then struck with a mallet, following the diamond’s natural cleavage to create the shape. This was risky, as the diamond would shatter if struck in the wrong place. Ground diamonds were then used to create an even, unblemished faceted surface, in a process called polishing. At this time, diamond cutters were still limited to the natural shape of the crystal.
Next came the table cut, in the mid 15th century. This expanded on the pointcut by removing a portion of the octahedron, creating a flat surface. This was created through a process called bruting, where one rough diamond is used to shape another. This surface is still referred to as a diamond’s table. Later table-cut diamonds also had a culet, which is the point at the bottom of a diamond’s pavilion, and facets. Both were introduced to reflect light, though the diamond’s brilliance was not seen in these cuts; in fact, at this point, diamonds still appeared black.
A big change came at the end of the 15th century, with the invention of the scaif. Invented by Lodewyk van Berken, the scaif was a polishing wheel that, using olive oil as a lubricant, used diamond dust to grind facets into diamonds. This machine enabled him to cut a much more precise stone, and concentrate on the reflection of light. It was in this period that the briolette cut became popular.
Throughout the 15th and 16th centuries, cutters used the scaif to produce more creative cuts. The rose cut made its debut during this time, as did diamonds cut to form rosettes. The rose cut featured a flat bottom, with triangular facets cut into the crown. Rosettes were a collection of small diamonds grouped together to form a larger-looking piece.
Diamond Cutting in the 1600s
It is in the 17th century that diamond sawing was introduced. This method involved a thin wire coated with a mixture of diamond powder and oil, that was then run across or through the stone, cutting it.
The first brilliant-cut diamonds were also introduced during this century. At the time they were called Mazarin’s, named for the designer, Cardinal Jules Mazarin. These early brilliants had 17 facets on the diamond’s crown, and the brilliance of the stone was significantly improved when compared to the previous rose cut. Next came the triple-cut or Peruzzi brilliants, named for the Portuguese diamond cutter Vincent Peruzzi. On these, the number of facets increased to 33, and again, offered an improvement in the diamond’s brilliance.
Though these were brilliant-cut diamonds, they are not the same as the brilliants seen today. The facets were not symmetrical, and the stones were usually rounded rectangles or squares in cross-section, rather than circular. However, they were similar to today’s brilliants in that they had a diamond- and triangular-shaped facets cut into the crown and the pavilion.
Diamond Cutting in the 1700s
Early in the 18th century, Peruzzi took his cut to the next level, increasing the number of facets to 58. This became known as the old-mine cut.
It is worth mentioning that although these various styles of brilliant-cut diamonds were being produced during this time, the pointcut and table-cut were still considerably more popular in the early 1700s. As the century progressed the brilliants did surpass the old cuts in popularity. By the end of the 18th century, old mine cuts, in particular, were very popular. They eventually evolved into the old European cut, which had a more rounded shape and a different facet arrangement.
Diamond Cutting in the 1800s
The most significant development during this period was that of the steam-driven bruting machine by Charles M. Field and Henry D. Morse. It was patented in 1874, and then an electric version was developed by 1891. With these machines came the first-round brilliant-cut diamonds.
Diamond Cutting in 1900s and 2000s
In the early 1900s, the first motorized diamond saw was invented, which was a blade coated with diamond dust and oil. This had a huge impact on the accuracy of diamond cuts, as cleaving was no longer required. However, it was more expensive than cleaving and took considerably longer. Nonetheless, it became the most popular method of diamond cutting and enabled more creative cuts. For example, the Asscher cut and the baguette-cut were both introduced during these early years.
In 1919 Marcel Tolkowsky published a book called Diamond Design, which had a huge impact on how diamonds were cut from that point forward. Up until this point, diamonds had been cut for either brilliance or dispersion– never both. Using a mathematical formula he developed a cut that would balance the two, creating the modern brilliant-cut diamond.
Since the Tolkowsky, there have been some changes in diamond design. The modern princess cut was developed in the 1960s, and in the 1970s Bruce Harding developed a new mathematical formula to cut brilliant diamonds. Since then some adjustments have been made to this diamond cut.
These days, diamond cuts are evaluated by both the AGS and GIA laboratories, based on light performance and proportions. The same basic machinery and methods are used for diamond cutting, though technological advancements have been made. For example, polishing is now done with a rotating polishing wheel, and cutting is sometimes done with a laser.
This article was contributed by Frank Fisher.