Nákupní košík je prázdný
For centuries, the price of a diamond has been directly proportional to its weight. Diamond jewels were only set with rough stones. It could not have been otherwise: as the hardest mineral on Earth, no one was able to work diamond. The change came at the turn of the 14th and 15th centuries. At that time, the Belgian Lodewyk van Bercken discovered a method of cutting a diamond with another diamond. Today, before being embedded in jewellery, the diamond loses on average half the weight it had as a rough stone.
Masterpiece of skill
An unworked and unpolished diamond looks like an uninteresting piece of glass It is only after working and cutting the facets that it develops its glory and shine. Only by studying the rough stone thoroughly is it possible to achieve as large a worked diamond with as few impurities as possible. This work requires tremendous experience as well as detailed knowledge of diamond crystallography and possible impurities present in the diamond. Subsequently, the final shape of the stone will be determined.
Brilliant – brilliant cut
The most common shape is the round brilliant cut. A typical round brilliant has a total of 57 facets: a table (the large facet in the centre), 32 facets on the crown (top portion of the diamond) and 24 facets on the pavilion (bottom portion of the diamond ending in a point). In cutting, it loses over half its original weight.
Other possible shapes are the marquise, oval, teardrop, heart, emerald, square, triangle, octagon, and many others. The result depends on the shape of the rough diamond and is also determined by fashion to some extent. Currently, we are seeing a large influx of new shapes onto the market.
Diamond processing step by step:
are laser marked on the stone, then it is cut and polished. Every diamond is unique, and the whole process is always specific to a particular stone. The yield depends mainly on the shape and quality of the rough material.
Cleaving
When cleaving, the rough diamond is split into two or more parts with a single strike along the internal cleavable lines, i.e. only in a certain direction. This technique has been used in India for centuries and requires great skill. Cleaving is carried out in parallel along the crystal. The diamond is mounted in a wooden holder and against it a second diamond called a sharp is mounted in a similar way; the sharp diamond is used to file a grove in the first. After a sharp blow with a mallet on a steel blade, the diamond separates into parts.
Sawing
Sawing is carried out against the direction of the crystals. Before sawing, the diamond is fixed in a copper head with a special plaster and limestone mixture. Once the mixture has hardened, the head is clamped onto the cutting machine. The diamond is sawn with an extremely thin blade to which oil and diamond grit is applied. The circular blades reach a frequency of 10,000 – 15,000 rpm. It is best to perform sawing at about one millimeter per hour. Sawing large stones can take several weeks.
Bruting
The bruting of a cleaved or already sawn stone gives the diamond its future shape. The traditional method is again to mount the diamond in a lathe head. Bruting is done by a second diamond mounted opposite, whereby the diamond gets its round shape.
Cutting
In cutting, facets are formed on the diamond surface. The diamond is clamped in special pliers of the faceting machine, called the quadrant, and set at an exact angle against the grinding disk. The grinding disk is made of steel and coated with oil mixed with diamond grit.
Tradition versus modernity
Although diamond processing is still frequently done manually, modern methods also play a very important role. For example, marking a stone before cleaving is done by laser, as is as sawing and shaping. When using a laser for sawing, it is not necessary to consider the direction of the crystals, but this way the diamond loses slightly more of its weight than would be the case with the old mechanical method.
Teamwork
Despite the indisputable advantages of modern technology, behind this process there always stand the indispensable human skills that turn the rough stone into a splendid gem. Many people are always involved in the creation of one diamond. The cut layout is usually done by one person, sawing and bruting by another two people, followed by at least two other cutters, called a blocker and a brillianteer. Small brilliant cuts called “melees” are produced literally in a series. Each type of facet is made by different cutter. These melees are produced exclusively in India and China, the bigger ones in Belgium, Israel and the United States.
5. 5. 2020
From the comfort of your home, you can be in regular contact with us. Online webinars where you can find out more information about precious metals, cooperation options or answer your questions.
30. 8. 2016
There is an only diamond mine in American state Arkansas which is open to the public.