Laser Inscription

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Laser inscription, a relatively new technology refers to a very small graphic or text being inscribed on the girdle of a diamond. The inscription is commonly a brand name, certificate number with laboratory name and/or a romantic message. The inscription is only visible with a jeweller's loupe, and even then can be difficult to read.


Prior to laser inscription, sealing diamonds in plastic packets was a popular way to prove that the diamond matched the certificate. Nowadays, a grading laboratory can laser inscribe the certificate number on the diamond's girdle, providing even more security over the sealing method.

However, it should be noted that laser inscription is not entirely fool proof. As Fred CuellarExternal Link explains:

Anybody can take an extra certificate and laser inscribe its number on a diamond that doesn't match it. Now it maybe true if some common thug stole your diamond having a serial number that matches your certificate might bring it back to you, but it is unlikely. All sophisticated jewel thieves have the girdles repolished to remove the laser inscription so the diamond cannot be traced. This of course dispels the notion that an inscription is permanent and cannot be removed.

Equipment Used

Equipment used to laser inscribe diamonds can cost up to US$300,000. This is reflected in the extra cost charged by grading laboratories to do laser inscriptions. Manufacturers of laser inscription equipment include TeoSysExternal Link and PhotoScribeExternal Link.

Hot vs Cold Lasers

There are two types of laser inscription, commonly termed "hot" and "cold". Cold lasers operate with a lower wavelength (eg 193 nanometers) and hot lasers operate with a higher wavelength.

"Hot" lasers make it a lot easier to damage a diamond, as this articleExternal Link explains:

Lasers with higher wavelengths will work when everything is set correctly, so they are appropriate for systems operated by experienced technicians. But many potential users of the less expensive 5X0 lack technical skills, so the chance for errors is far greater.

That's where the type of the laser and its wavelength become important. Lasers at wave-lengths above 217 nm can crack the diamond if they are not focused precisely on the diamond's face. "If you focus beneath the surface of the diamond, you can create fissures, it's almost like blasting with dynamite that's put inside a rock wall," Church says.

However, as the manufacturer of "cold" laser inscription equipment admitsExternal Link, "cold" laser inscription equipment can still damage a diamond if the laser is focused on one spot for a long enough time.

Real Life Examples

Below are some examples of laser inscription:

Hot Laser Inscription

An Example Of Hot Laser Inscription

Cold Laser Inscription

An Example Of Cold Laser Inscription

As you can see, "cold" laser inscriptions can be difficult to see, especially under frosted girdles.

Where To Get Your Diamond Laser Inscribed

Most international labs such as the GIA, EGL and HRD have laser inscription services. In Australia, the DCLA offers "cold" laser inscription services.