From Planning to Polished: The Technology of Polishing

For years, cutting and polishing have been moving away from the traditional diamond centers in Europe, Israel and America in favor of lower-wage nations like India and China. In addition to the wage differential, this skills transfer has been at least partially driven by the closing of the technology gap. Developing nations have acquired, and in many cases developed, their own machinery and software. This has helped to streamline the diamond cutting process, making it far more efficient than it was even a decade ago.

Diamond manufacturing is a fascinating blend of modern technology and old-world tradition. Functions like planning, mapping, and sawing are far more sophisticated today as a result of technology. However, faceting is still done today much as it has been for centuries. As we continue to explore the manufacturing arm of our industry, I want to take a closer look at the role that technology is playing in its development, and at the implications for the coming years.

It is important to note, however, that technology has not only been beneficial to the manufacturing sector. Retailers, miners, and even consumers have found new applications for technologies that have changed how they operate in an industry that still clings to its traditional ways. However, I think it is the midstream of our industry that has likely been the most profoundly impacted as a result of advancing technology.

Planning and Mapping

I have watched the development of mapping machines with much fascination over the years. These sophisticated machines, driven by modern software, have taken the guesswork out of planning how to cut a rough stone, and have also made it possible to profitably cut complicated stones that might once have been destined for only industrial use. I have personally witnessed a large but very complicated rough diamond, that at first glance seemed to be of very poor quality, that went on to produce more than twenty D Flawless polished diamonds. Mapping software can see inside the heart of the rough stone, and design a sawing and polishing plan to maximize yield and profit.

Typically, each company will integrate its own unique pricing structure for polished gems with the planning software. This allows the software and its operator to make calculations to maximize profit, and helps the manufacturer to quickly make adjustments for particular cuts or sizes that may be in or out of demand at any given time. Once planning is complete, some machines can even mark the stone using laser inscriptions that tell the sawers and cutters how and where to start.

Israel has always been at the forefront of technology development in the diamond industry, and this has not changed. But Indian firms are catching up. Israeli companies like Sarine & OGI Systems were market leaders in the development of planning machines dating back more than 25 years. However, new entrants such as India-based Lexus India and Sahajanand Laser Technologies are getting good exposure outside of India, notably in Antwerp.

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LASERs

Lasers are at the heart of diamond cutting technology and the power and applications for LASER have grown exponentially since it was first invented and trialed in 1960 at Hughes Research Laboratory in Malibu, California. Interestingly, the development of the laser would set off a 28-year patent infringement lawsuit between Bell Labs and Mr. Gordan Gould, a Columbia University graduate student who was developing a laser at the same time as Bell Labs. The issue of who best deserves credit for the invention of the laser remains unresolved by historians.

The diamond industry has used lasers for sawing and shaping stones since around the turn of the 21st century. Older technology relied on rotating bronze disk saws impregnated with diamond dust for cutting. Cutting with these older saws was time-consuming and generated significant amounts of heat that often necessitated stopping the process while things cooled down. Typical weight loss from a bronze saw was 2%-4%, compared to around 1% with the thinner laser beam. Lasers have also opened up opportunities to make ‘wedge’ cuts that can shape the rough stone in advance of bruting.

The precision shaping ability of lasers has enabled some adventurous manufacturers to develop new diamond shapes that would previously have been impossible to create. Horse heads, butterflies, stars, and letters for initials are just a few examples of experiments in diamond shaping. Lasers are also used frequently in finished diamond inscription. Brands like De Beers Forevermark and GIA use lasers to imprint tiny tracking codes and logos on the girdle of their stones for identification purposes.

India-based Sahajanand Laser Technologies is at the forefront of laser cutting technology in the diamond industry, and the company claims to have sold more than 1,000 laser sawing machines to the Indian and international diamond communities.

Mechanical Bruting

Mechanical bruting machines have been around, in some form or another, for a long time. The first steam-driven bruting machines were invented in the 1870s by Henry D. Morse and Charles M. Field. These would give way to an electric version, first built in 1891.

These machines have obviously grown much more sophisticated since then. Bruting (or girdling) has taken on even more importance in recent years, as consumers and diamond investors now demand perfection in diamond cuts. This often begins with the bruting process, which lays the foundation for the final shape of the stone.

While lasers can do an excellent job of shaping the diamond, only diamond-to-diamond cutting is suitable for the final surface of the stone. The more recent development of bruting machines that can form fancy-shaped diamonds has simplified their manufacturing and opened up a variety of new cuts, helping manufacturers to increase finished yields in a meaningful way.

Automated Faceting Machines

In recent years, automated faceting machines have developed to the point where the machines are challenging experienced human polishers for supremacy. Using bands of light to map out the curvature of the stone, these AFMs have proven successful in polishing to a very high EX-EX-EX standard, in some cases with reduced weight loss compared to the work of human polishers. These pieces often rely on sophisticated axels that allow the diamond to be rotated into any desired position.

The challenge with these machines has been their high cost relative to human cutters in low-wage nations. These machines can have a payback period of three years or more for diamonds, and this can be even longer for those working with other precious gemstones. Generally, these machines would still require modest intervention from a skilled operator to set the stone and program the software to cut it appropriately. For now at least, faceting is still done largely by human hands. Interestingly, Germany is at the forefront of development for these machines, followed by Korea, India, and China.

Rough Diamond Purchasing

Of course, before any manufacturing can take place, cutters must first acquire rough diamonds. After a stone is bought, planners can take all the time they need and utilize sophisticated planning software to plan out the final polished stone. However, rough buyers often must make purchase decisions with far more limited time to study the stone(s), and this usually takes place in someone else’s office where the buyer does not have access to the same technology that they would in their own office or factory.

Portable analysis machines are helping to bridge the gap. It is not uncommon to see a team of rough diamond buyers with suitcases full of gadgets that can be used to study rough stones outside of their own facilities. These might include color machines, tension scopes, microscopes, fluorescence lamps, and portable mapping machines that can be run from a laptop computer.

Rough Sorting

Used by both miners and manufacturers alike, rough sorting machines can help to automate many time-consuming processes. Machines have been developed that can sort diamonds according to a variety of classifications such as their model (shape), color, and size. The manual process of sieving diamonds is now largely mechanical, using large sieve shakers that agitate a parcel of rough stones across metal sieve plates with gradually smaller holes, so that diamonds can be quickly sized and sent to the appropriate department or individuals for cutting.

The truth is, entire books could be written to discuss how technology is being used in the diamond industry. Many centuries-old techniques have been rendered redundant by machines and the standards of manufacturing have been improved as a result. These advances are helping to deliver a better product to the consumer, and making manufacturers more efficient in their operations. We should all watch what happens with anticipation, as the next big advance is always on the horizon.

The views expressed here are solely those of the author in his private capacity. No one should act upon any opinion or information on this website without consulting a professional, qualified adviser.