The art of cutting diamonds.

Know your diamonds.

A Lapidary’s Factory

Before a rough diamond comes through the door of our factory, preparations for that specific diamond starts with an intense journey of calculations, measurements and evaluation.

Ishaia Gol would travel to Antwerp on a monthly basis visiting different tenders, going through the process of evaluation and bidding on roughs several times in one day. After buzzing through multiple levels of security, holding a suitcase in each hand, he enters a meeting room. The large windows let in an abundance of natural light and the carpet of the floor protects a diamond from bruising should it fall. One suitcase contains a small microscope, tweezers, a scanner and a few other essentials. The other suitcase holds a camera, notebook, markers and a calculator. He studies the piece of rough, making notes on what it can potentially yield. After making his evaluation he carefully packs up his equipment, possibly leaving a bid on the stone. Then, he begins the process all over again with a new sight holder in another office. Several hours and stones later, Ishaia heads to the airport for New York with 3 bids on the table at a combined value of $10,000,000.00. (read more in “A Gemologist and his Gems”)

Cutting Process

1. Mapping

The diamond cutting process is a long and meticulous journey. It starts out at the pre-planning stage. Before any kind of cutting can be done, the diamond cutter must analyze the rough stone and determine what shapes could come out of it.

The goal is to use as much of the rough stone as possible, so a diamond cutter will opt to develop that stone into a shape that will minimize waste. A rough stone is also mapped, using high-tech software to ensure that each facet is the same dimensions throughout.

Through this software, the cutter is able to demonstrate how much of the rough he will be able to use and how much he will loose, were he to cut it for that specific shape. The software allows a visual, yet changeable look of what could be before it actually is.

2. Cleaving

Next, the rough stone goes through a process known as cleaving. This is where the rough stone is split into two, allowing a diamond cutter to work on each piece.

The stone is cut at its weakest point, and the pieces are held together by a mold, usually made of cement or wax.

3. Sawing

After cleaving is done, the diamond cutter is ready to saw. Currently, diamond cutters are using a phosphor-bronze blade to saw through a diamond.

This blade spins at about 15,000.00 rpm, letting it slowly cut through the stone.

4. Bruiting and Cutting

Bruiting is a process not all shapes go through, just round brilliant. This is the act of creating the girdle, also referred to as girdling. Generally, diamond cutters use machines to do bruiting process, but there are still some cutters who work by hand, using diamonds to cut diamonds. 

When they cut by hand, they place the diamond pieces between cement to hold it in place while they cut the different facets. During the bruiting process done by machine, diamonds are placed in what’s known as a lathe. A second diamond is rubbed against it in the machine creating that polished girdle.

5. Polishing

Following the cutting process, a diamond cutter now moves on to polishing. This process makes the diamond have its shiny and finished look. The stone is covered in diamond powder and placed against a rotating polishing wheel.

This step can be split up even further. There are two more sub-processes during polishing that a diamond goes through: blocking and brillianteering.

Blocking is done to create 8 mains to the pavilion, 8 crowns, 1 table facet, and 1 culet to the stone. It serves as the base of any single cut diamond.

Brillianteering is the one of the last steps within the polishing process and the entire cutting process. This is arguably one of the most meticulous processes, as it will make or break the stone’s reputation for fire and brilliance.

During this step, all other facets are developed and studied to find out the best sort of brilliance the stone is capable of showing.