Scientists at the Lebedev Physical Institute (LPI) in Moscow have developed three-dimensional diamond marking techniques that could be employed by jewelers, the Institute announced through its own news agency FIAN-Inform.
“Most of the diamonds produced in the world, about 80% of those, are only fit for technical uses. The remaining 20% are of jewelry quality and much more expensive. The price varies considerably depending on the weight and quality of a precious stone; therefore the development of nondestructive diamond markings that can’t be seen with the unaided eye, according to the Kimberley standard, is of paramount importance for today’s jewelry industry,” FIAN quoted Andrei Ionin, the head of LPI’s gas laser lab, as saying.
One of the two methods developed at LPI is based on the impact that femtosecond laser emission has on a diamond. The emission is said to create in the precious stone an increased concentration of what physicists call ‘vacancies,’ or defects in a diamond’s crystal lattice that have no carbon atoms. This enables the researchers to get a clear picture of how the stone is structured.
In the other technique, femtosecond laser emission is also used, but this time amorphous carbon phase inclusions are created in a diamond instead of vacancies. The inclusions can be seen through an optical microscope but not with the unaided eye.
“Femtosecond laser emission can be focused on different depths inside transparent materials, a technology that helps create a unique 3D marking. In our experiments, we have succeeded in forming three-dimensional micro-scale labels on both artificial and natural diamonds,” said Sergei Kudryashov, a senior research fellow at LPI.