Skip to content

Why Are Lasers Used To Write Inside Diamonds?

The inscription was created using a proprietary technology developed by Oxford-based Opsydia.

Its machines are the only ones on the market capable of penetrating a diamond's surface and manipulating its atoms. The logo I'm looking for is only about half a millimetre wide. I can't see it, despite instructions from Lewis Fish, Opsydia's head of product. "It's very difficult," he admits. "They're purposefully fine, and they're really aimed at trained jewellers." But who would want to scribble on the inside of a diamond? "The big thing in the industry right now is traceability and transparency," says Andrew Rimmer, CEO of Opsydia.

He believes that Opsydia's technology can improve on the current methods for identifying diamonds. There are already systems in place to track a diamond from the time it emerges from a mine as a rough diamond, through the cutting and polishing process, and all the way to the retailer. However, the procedure is far from perfect. Human Rights Watch (HRW) chastised jewellers last year, claiming that many could not identify the mines from which their diamonds were mined. According to HRW, this is significant because "labour rights violations, violence, and other abuses have remained a serious problem in gold and diamond mining."

It is also becoming increasingly important for diamond sellers to be able to differentiate between those that have come from mines, known as natural diamonds, and the growing number of lab-grown diamonds. The technology for producing lab-grown diamonds is constantly improving, and they are a rapidly growing segment of the market. However, because natural diamonds are significantly more expensive than lab-grown gems, it is critical to have a reliable way of distinguishing them.

Mr. Rimmer explains that his systems can provide failsafe verification by inscribing data inside the diamond - data that cannot be removed but does not devalue the gem in any way. "People who make diamond jewellery want to be able to show the consumer that this is a natural diamond from an ethical source," Mr Rimmer says. The diamond-inscribing machine used by Opsydia is the size of a large photocopier. A pulsed laser inside emits very short laser bursts.

At very small scales, such high-powered bursts can precisely manipulate materials like diamonds and other gems. However, simply pointing the laser at a diamond is insufficient because the diamond's structure scatters the beam. "Diamond is about the most difficult transparent material to process with lasers," Mr Rimmer says. The Opsydia system tunes the laser so that it can pass through the diamond's surface to a depth of about a quarter millimetre. Instead of bouncing around the diamond at random, the laser comes to a pinpoint focus to create the inscription to the client's specifications. If the diamond requires an identification number that is invisible to anyone who does not have a powerful microscope, the system can change the diamond at the molecular level. If a jeweller wants to make its logo visible, the laser can be used to make larger changes to the carbon structure of the diamond.

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT