When we think of diamonds, we automatically imagine beautifully cut stones filled with light, not a dull rock. Cut diamonds are designed to exaggerate the crystal’s reflective surfaces, making it appear bright and glittering. To do this, the rock is cut precisely using a laser.

Lasers are effective for cutting all sorts of materials but are particularly useful for cutting diamonds. Before the advent of laser cutting, diamonds were cut using diamond saws. This process is still used sometimes, but it is lengthy and any mistake could result in the stone shattering. Lasers are a much safer option.

So how does laser cutting diamond work?  

The Five Processes of Laser Cutting Diamonds

What is a Neodymium YAG Laser?

The neodymium YAG laser is often used to cut diamonds to high precision using infrared light rather than visible. YAG stands for Yttrium Aluminium Garnet, and is the synthetic crystal. Yttrium is a good material to use as the neodymium is of a similar molecular structure and therefore combines with the crystal easily. The neodymium is used to dope the crystal and is what makes it possible for the laser to be produced.

Advantages Neodymium YAG Lasers

The neodymium YAG laser cuts the stone in only two passes. The high heat of the laser leaves black marks where the diamond is converted into graphite. The graphite could be as small as 20 microns across so it is easily burned away with the second pass of the laser.

The advantage of using the laser instead of the traditional method of cleaving or the diamond saw is its extreme precision. Together with computer technology, lasers can cut diamonds more accurately and leave no cutting edge that would require wearing down. Lasers are also less likely to warp the diamond because the heat is confined to a narrow space.

The Best Cut for the Most Light

The main aim of diamond cutting is to show off the diamond’s natural sparkle. To do this, the diamond needs to reflect as much light as possible from the top face of the crystal. The brighter the crystal the higher it’s value so getting the cut right is of huge importance.

Image showing the optimum cut for the most reflective diamond.

Image: ross-simons.com

There are all sorts of different shapes of diamonds but the round cut is the best for producing the most brilliant diamond. This cut works particularly well for smaller stones because most rough diamonds are shaped in such a way that two round brilliant diamonds can be cut losing the least crystal.
Using lasers to cut diamonds has made the process faster, more efficient and more effective. So next time you see a cut diamond, now you’ll know how it was made.