IDENTIFICATION MARK TO MARK VALUABLE ITEMS AND VALUABLE ITEM WITH ITS APPLICATION Russian patent published in 2011 - IPC A44C17/00 G09F3/00 G03H1/00 

FIELD: personal use articles.

SUBSTANCE: invention relates to an identification mark to mark valuable items, preferably precious stones, and to a valuable item with its application. The identification mark to mark valuable items is arranged in the form of an optically visualised image formed on a polished surface of the item and arranged as a diffraction structure, in particular, of microstrokes of sinusoidal profile. The diffraction structure is arranged as a reflecting phased diffraction grid, which functionally is a facility to increase contrast and to vary a colour tone of radiation spectrum, at the same time microstructures of the diffraction structure are made at the depth, which does not exceed the permissible value of microirregularities in the generally accepted technology of precious stones polishing. The image of the mark is made with geometrical dimensions, sufficient for its visual perception at the angle of diffraction in the reflected light with the naked eye without additional magnification, at the same time shape and relative space arrangement of microstructures in the diffraction structure are realised with holographic accuracy ensured by means of interfering coherent laser beams.

EFFECT: invention ensures high contrast of the mark and minimises deterioration of marked surface quality.

3 cl, 7 dwg