Laser inscriptions: Carved in diamond forever!

Laser inscriptions have very little to do with Star Wars or The Force, but are perhaps more important for your diamonds than you think.

A standard laser inscription is a combination of letters and numbers “engraved” in a diamond using a laser. In most cases it is marked on the stone’s girdle (Fig. 1), but other parts such as the crown or even the table are possible although highly unusual (Fig. 2).

A laser is a high-energy bundle of light which is used to “burn” the symbol onto the diamond. The burning process is actually a “graphitisation” of the surface, where the strong carbon-carbon bounds of diamonds are destroyed. HRD Antwerp Diamond Lab uses a “cold” laser with a wavelength of 193 nm. It allows very precise inscriptions. The letters and numbers of a standard inscription are around 50 µm in height, and only a few microns in depth. For comparison: an average human hair has a thickness of around 70 micron. It needs to be stressed that a laser inscription does not affect the overall appearance or the clarity grade of the diamond. Laser inscription can also be removed by repolishing the stone, a service that HRD Antwerp also provides.
Every year HRD Antwerp inscribes several tens of thousands of diamonds. Laser inscriptions are more and more in demand because of a number of reasons:

Security:

The combination of letters and numbers serves as a unique ID that helps to identify a particular stone if needed, because the letters and numbers are the same as the ones on the accompanying certificate. This makes it easier for the client to verify if they’re dealing with the correct diamond. So in most cases a laser inscription is used as a protection against fraud, as diamonds are usually laser inscribed by the grading lab at which they are certified.

Recently the market has seen an increase of treated and lab-grown diamonds available for the end consumer. Also in these cases the laser inscription is used to clearly differentiate between natural, treated and laboratory-grown diamonds. Synthetic diamonds get a laser inscription “Lab Grown [certificate number]” stones that have been HPHT treated are characterized by “HPHT [certificate number]”.

Branding:

More and more laser inscription are used as a branding or marketing tool. Usually the name of the company or the special cut (Fig. 3) and/or logo are inscribed. In the beginning of the 2000’s, for example, in the wake of the Conflict Diamond Issue, Sirius Diamonds, a Canadian company, engraved small polar bears on their stones to emphasize the conflict-free origin of their diamonds.

Personal comments:

Besides the branding done by companies, some clients like to add personal messages, or even a photograph. Writing “I love you!” on a diamond does make it more forever! Carved in stone, so to speak…(Fig. 4).