When diamonds emerge from the earth, they are rough and unrefined. It takes hours of cutting and polishing to turn a rough diamond into the beautiful stone we know it as, but have you ever wondered how exactly that happens?
Technically, diamond cutting is the practice of changing a diamond from a rough stone into a faceted gem, or what we see when we think of a diamond. Diamond cutting is extremely difficult. It is a highly specialised process that requires years of training as well as knowledge, specialised tools, equipment and techniques.
Cutting consists of 2 main aspects:
- Shape - round, square, oval etc
- Quality of the cut – the value of the diamond will vary greatly depending on the quality of the cut
Diamond cutting, as well as overall processing, is concentrated in a few cities around the world. The main diamond trading centres are Antwerp, Tel Aviv, and Dubai. There are also processing centres in India and China.
The diamond cutting process consists of 4 steps
- Planning – the rough diamond is analysed to determine how it will be cut. Scanning devices are used to get a 3-dimensional computer model of the rough stone. Inclusions are photographed and placed on the 3D model, which is then used to find an optimal way to cut the stone. The rough diamond is then marked to outline the best possible shape and cut
- Cleaving or sawing – Cleaving is the separation of a piece of diamond rough into separate pieces, to be finished as separate gems. Sawing is the use of a diamond saw or laser to cut the diamond rough into separate pieces.
- Bruting - Bruting is the art of cutting a diamond round. In the modern era diamonds are rounded using either a laser; a diamond disk, impregnated with diamonds; or two diamonds cutting against each other. Industrial diamonds can also be used for bruting a diamond round. Modern computer software measures the roundness of each diamond and "Ideal Cut" diamonds have to round within a 10th of a millimeter to qualify as an excellent cut diamond
- Diamond polishing is the final polishing of the diamond. The facets are cut onto the diamond and final polishing is performed. Since diamonds are one of the hardest materials, special diamond-coated surfaces are used to cut and polish the diamond. This step gives the diamond its brilliant sparkle that we know so well.