METHOD AND SYSTEM FOR LASER MARKING PRECIOUS STONES, SUCH AS DIAMONDS Russian patent published in 2009 - IPC B44B7/00 B28D5/00 G01N21/87 

FIELD: physics.

SUBSTANCE: present invention relates to the method and system for laser marking precious stones and, particularly to the method and system for engraving authentication codes. In the system for laser marking precious stones such as diamonds, marks consist of several microscopic dots, increase of which can be initiated upon effect on natural internal defects or impurities inside the precious stone of a strictly focused laser pulse sequence. The marks are inscribed by laser pulses, carrying significantly less energy than threshold energy required for inscription inside ideal material of precious stone. The method of laser marking and encryption takes into account random spatial distribution of defects, present in natural precious stones, as well as their much localised character. Authentication data are encrypted in the precious stone in the relative spatial arrangement of dots which form a mark. Dots, engraved under the surface of the precious stone, can be made undetectable to the naked eye and a magnifier through limiting their individual size to several micrometres. The mark can be detected using a special optical reading device.

EFFECT: laser inscription of permanent point marks inside precious stones.

40 cl, 14 dwg