Diamond and Gemstone Faceting

Facets are flat, geometric faces that lie on the surface of objects. They play a major role in diamond and gemstone manufacturing, where they are finely engineered to add to the stone’s natural radiance and shine. The faceting procedure is largely a scientific method and one that has undergone considerable research in the last century. The amount of facets that are in the stone is reliant on the type of cut that it is being made into.

As a result, the cut of the stone is the most important factor in showcasing its brilliance and determining its value. Ironically, it is also the only factor of the stone that is purely under the control of a human, as opposed to the natural formation. A desirable, well-faceted cut can make even the lowest quality of stones look incredible. On the opposite side, a flawless, colourless diamond can appear of poor quality if not cut properly.

There are four basic steps behind the faceting process: Planning, cleaving/sawing, bruiting, and the polishing stage. This involves a lot of attention and detail, as each of the shapes created during faceting must be in exact, geometric relation to each other. This enforces the theory of symmetry onto the stone, which is very important for the stone’s fire and brilliance to shine through properly.

Planning

Before the diamond can be cut and faceted, a cutter will undergo a lot of planning and design work. This involves inspecting the stone to see the best way it can be carved up, determining the cut types that will be used, and where to mark the stone itself to create the most profitable gems.

Cleaving/sawing

Now the stone is ready to be broken down into little gems fit for use in jewellery. There are two different ways to break the stone down. Sawing is done with the use of laser guides and is often quicker and much easier for the cutter. Cleaving involves the old-fashioned method of using a pick and a hammer and presents a degree of error if not done correctly.

Bruting

Bruting involves using another diamond stone to fashion the gem into the desired shape. They are held against one another and spun on a rotating lathe in opposite directions to create friction. The bruting process is also known as girdling, a reference to the term used for the outermost point of the stone’s exterior from its centre.

Polishing

The polishing process involves properly faceting the stone, as well as providing it with a clean look for the retail sale. Seventeen to eighteen facets will be made into the diamond initially, allowing the polisher to determine the symmetrical aspects of the gem. The polisher will also seek to maximise the brilliance of the stone during this step.