Diamonds Cut And Polished From Roughs

How Are Diamonds Cut And Polished from Roughs?

Diamond cutting is the process that takes a rough diamond and changes it into a shaped and beautiful gem. The process must be undertaken by a professional with expert knowledge, equipment and tools for the job since every single decision made will affect the outcome of profitability.

So, what are the main considerations a cutter take into account when planning to cut a diamond? The first choice to make is to decide on the shape itself; round, oval, pear etc. And secondly, the proportioning of facets and quality of the cut (i.e. symmetry and polish) are planned with computer simulations.

The Diamond Cutting And Polishing Process

Since diamonds are made of the hardest material in the world, only a diamond can be used to mechanically cut another diamond. Lasers are another alternative but their uses are largely limited to the cleaving and bruting purposes. Usually, the tools used in the workshop consist of diamond-bladed edges or discs that are lined in diamond dust.

The actual process of how diamonds cut from rough and polished can be broken down into five steps: planning, cleaving, bruting, polishing and inspecting.

• Stage 1: Planning a Rough Diamond

Planning to cut a rough stone is one of the most important things to get right. While it can be a time consuming process, this is also the step that determines the final value of the finished products.
 

In the planning stages, the cutter will figure out the best possible shapes of the diamond in order to minimize waste and maximize the yield of the rough stone. Typically, the rough stone is mapped with a Sarin machine to generate accurate measurements.

With this data, a computer software is then used to formulate 3D models that will show the cutter the best ways to optimize the rough.

• Stage 2: Cleaving/Sawing a Rough Diamond

The cleaving process is the part that involves splitting the rough into separate pieces. This will then allow the cutter to work on the pieces separately and also to utilize the rough fully.

Mechanical sawing can also be undertaken at this stage. In the case of oddly shaped roughs, the sawing process can also be undertaken with contactless cutting tools like lasers.

• Stage 3: Mechanical Bruting to “Round” the Roughs

After the diamond is split, bruting is then performed to make the separated rough stones round. This is process is also known as girdling. What happens here is that two diamonds are placed on a spinning axle across each other. They will then turn in opposite directions and grind against each other to create a rough girdle finish.

• Stage 4: Polishing the Diamond Facets

Once the rounded shape of the rough is formed, the next stage is to create and form the facets of the diamond. The cutter places the rough on a rotating arm and uses a spinning wheel to polish the rough. This creates the smooth and reflective facets on the diamond.

Interestingly, this polishing procedure is further divided into 2 steps: blocking and brillianteering.

In the blocking process, 8 pavilion mains, 8 crowns, 1 culet and 1 table facet are added to make a single cut stone. The importance of this step is to create a template for the next stage.

The brillianteer will then finish up the job by adding in the remaining facets and bringing it to a total of 57 facets. He holds great responsibility as the fire and brilliance of the diamond is determined at this stage.

• Stage 5: Inspecting the Polished Diamond (Quality Control)

The last stage is the inspection process. This is where the diamond is checked to make sure it meets the specifications set out by the manufacturer. If need be, the stone would be sent back to the polishers for some touching up if it didn’t meet the quality control standards.

The Grading Report For Quality Assurance

Once a diamond has been cut, they are usually sent to the gemological labs for a grading report to be obtained.
This will not only increase the value of the diamond but will also help people buy the stone with confidence.