METHOD FOR APPLYING MARK ONTO SURFACE OF DIAMOND OR CUT DIAMOND TO DETERMINE ITS AUTHENTICITY Russian patent published in 2017 - IPC G01N21/87 G01N21/956 B41M5/24 B23K26/352 C30B33/04 

FIELD: security.

SUBSTANCE: invention relates to a method of authenticating an article in the form of a diamond or a cut diamond. Identification mark invisible with the naked eye is applied onto a diamond or a cut diamond by exposure to a laser radiation with a wavelength exceeding 500 nm with simultaneous affecting by ultrasound using a tool located on the section surface. After that saved are at least two interference images of the article identification mark by means of a probing radiation with waves of different lengths together with data on location of a certain section of the article and an angle of incidence of the probing radiation. Determination of authenticity and correspondence to the saved values is carried out by directing the probing radiation onto the said section to create at least two interference images of the identification mark, which then are compared with the saved interference images, matching of which denotes the mark authenticity.

EFFECT: technical result is ensuring uniqueness of the mark, protection from counterfeiting and reliable identification during authentication.

4 cl, 2 dwg, 2 ex