Diamonds take millions of years to make and can even be dated back to over 1 billion years ago! Geologists believe that these gems are made in the mantle layer of the Earth and brought up to the surface by volcanic eruptions. Today, diamond mines are found across the whole world; from Africa to Australia, the diamond industry is one of the largest. So how do these crystallized gems go from mine to market?
From the Mine to Purchase
The first step large diamond corporations need to take is finding a geographical source. It takes an expert geologist to follow a trail and analyze the soil, looking for large sized crystals. Once a location is found, soil is extracted and transported to special operating plants where it is processed and rough diamonds are extracted. It can take hundreds of tons of soil just to find a single carat of rough diamonds that can be cut for a gem. Since large diamond mine corporations own the diamonds, they have their own private auctions and sales of uncut diamonds. Of these organizations, one of the largest is De Beers, selling uncut diamonds for many years. Depending on the size and color of the uncut diamonds, their sale can yield anywhere from a few hundred to a few million dollars.
Finding a Diamond Cutter
Now that a rough, uncut diamond has been found, finding the right diamond cutter is the most important part of the process. Diamond cutting requires special knowledge, tools, and techniques that take years to master. Types of diamond shapes include square, oval, rectangular, etc. The name of the cut is generally based off of the way it looks.
Buying loose diamonds is a form of alternative investment. Most of thee buyers have their own private diamond cutters that work exclusively for them. While some diamonds are named after their owner, it is common for the diamond to be named after the diamond cutter as an homage to the talent and devotion it takes to create the finished product. Check out this list of famous diamond cutters.
Cutting the Diamond
Before the cutter can begin the steps to diamond cutting, they have to plan and analyze the rough stone from an economic point of view. The main question for them is “How can I get the highest return on investment?” Things to consider are:
- Maximizing the stones value
- Retaining the stone’s weight
- Keeping the stone’s color as cutting can potentially change the way a diamond looks.
The first step of diamond cutting is cleaving; a rough diamond needs to be chopped along the stone’s tetrahedral plane (this is where it’s the weakest). Cutters place the stone in cement so the diamond doesn’t move and slices a sharp groove along the plane. The cutter then strikes the diamond, splitting the rough diamond into two. Note that this is only used for larger rough diamonds that are unmanageable unless cut into smaller pieces such as the Cullinan Diamond.
If cleaving isn’t an option due to a weak plane, the diamond cutters use a saw with a phosphor-bronze blade rotating at 15,000 rotations per minute (RPM). To put this into perspective, an idle car engine has an RPM of about 2,000.
This next step is where diamonds get their shape, its called bruiting. Bruiting is a technique that uses a diamond to cut another diamond since the cutter relies on the hardness of the stone. Bruiting can be done by either hand or by machine, depending on the size of the diamond and the preference of whomever is cutting it.
Finally, the now cut diamond needs to be polished. Polishing the diamond gives it the finished look. The diamond is put in a polishing wheel and the wheel is layered with a special powder that smooths the stone when it’s pressed against the wheel.
The stages a diamond has to go through to become a beautiful, glamorous gem literally take millions of years. From the moment it was created in the Earth’s mantle, to the polishing of a stone, it’s clear why the diamond world is intricate and luxurious.
For more reading on colored diamonds and how they're mined, see the links below:
- Inside the Mine: Top Colored Diamond Mines
- The High Cost of Mining Colored Diamonds
- Do You Know How Many Diamond Mines Exist Today?
- Striking it Rich at Arkansas Diamond Mine!