Diamond Cutting
To the untrained eye, a rough diamond can look like a piece of glass. An experienced diamond cutter is needed to bring out the hidden brilliance and beauty of a diamond. While the origins of diamond cutting can be traced to India, the first signs of a diamond cutting industry is believed to have begun in Venice around 1330.
The first major diamond cutting industry was established in Antwerp and Amsterdam where the majority of skilled craftsmen worked. The beginnings of diamond cutting were rather primitive as chisels and mallets were the tools used to shape diamonds. Craftsmen would find points of weakness in the diamond's structure and they would place the chisel at this point and cleave the diamond with a mallet. This was a delicate task, as cleaving in the wrong place would result in a shattered diamond. Afterwards, the newly shaped diamond was placed in a dop, an egg-shaped tin cup, and another diamond was used to further shape it. Since diamonds can only scratch other diamonds, the process of bruting was very slow and exacting.
Towards the end of the 15th century, a Jewish diamond cutter from Antwerp named Lodewyk van Berken created a new device called a scaif, which greatly impacted the process of diamond cutting. A scaif was a simple polishing wheel sprinkled with a mixture of oil and diamond dust and when the rough diamond was held against the turning wheel, the cutter was able to grind the rough diamond at certain angles to maximize the amount of light it reflected.
As van Berken originated from Antwerp, diamond cutters the world over flocked to the city to study his techniques. Thus, Antwerp became and still is a prominent diamond center.
The 20th century has brought another set of innovations for the diamond cutting industry with the advent of the diamond saw, Marcel Tolkowsky's formula for the ideal proportions of a round brilliant diamond and the Pieromatic diamond-cutting machine.
The diamond saw is similar to the scaif in terms of using oil and diamond dust, but instead of a wheel, a circular steel blade is employed. Using the saw is an even more painstaking process than cleaving and is also more expensive because it uses more diamond dust than the scaif. The advantage of the saw, however, is its ability to shape a diamond without destroying it. Moreover, it was easier to train workers to work the saw instead of teaching them how to cleave diamonds.
Before Tolkowsky discovered the proper mathematical proportions to bring out the pure brilliance of a diamond, diamond cutters had to rely on their own experience and trial and error to achieve a beautiful gem. With his formula, a diamond cutter was able to maximize the amount of light a diamond reflected with relative ease.
The introduction of the Pieromatic diamond-cutting machine, along with Tolkowsky's proportions, allowed diamond cutting to become a more efficient process. Diamond cutters could be trained in a few months to learn how to operate the machine instead of learning from master craftsmen, a process that would take much longer.