MARKING DIAMOND

摘要

In order to produce on the table of a diamond gemstone (7), an information mark which is invisible to the naked eye using a x10 loupe, an ultraviolet laser (1) having a wavelength of 193 nm is used in association with a mask (2) to irradiate the surface of the stone (7) at a fluence of less than 2 J/cm2 per pulse and with not fewer than 100 pulses, in the presence of air which reacts with the diamond (7) and causes the mark to be formed without any darkening which is visible when viewing using a microscope.