IDENTIFICATION MARK FOR MARKING VALUABLES AND METHOD OF MAKING SAID MARK Russian patent published in 2009 - IPC C30B31/22 B44B3/00 A44C17/00 G01N21/87 

FIELD: physics.

SUBSTANCE: invention relates to apparatus and methods of marking valuables, mainly precious stones, particularly cut diamonds, and can be used for subsequent identification of data of the valuables. Mark 1 is made in form of an image, which is optically visualised in diffraction-reflection light, made on the polished surface 3 of the valuable object 2. The structure of the image is formed by a modified area of the surface layer of the object 2 with optical properties in the said area, which is functionally the image of mark 1, altered from the initial properties. The modified area is made in form of microlines 8, spatially formed according to type of the reflection grating, which is functionally an apparatus for increasing contrast of visual perception of the image of marker 1 in at least one of the colour hues of the spectrum of incident radiation. The structure of microlines of the modified area includes at least one impurity additive, which is selected from a group which includes noble metals or boron, ion-implanted into atomic lattices of the initial material of the object without breaking interatomic bonds of these lattices and, therefore, without changing quality of the polished surface of the object, but with change of the complex refractive index of this material. According to the method of making mark 1, before modification, a technological layer (TL) of material, which is removed after modification, is deposited on surface 3. A structure is formed in the technological layer according to type of the line grating. The corresponding area of the surface layer is modified by exposing this area to an ion beam through a mask with an image of mark 1 and the spatial structure formed in the technological layer, that way creating process conditions implantation of modifier ions into the modified area of the surface layer of the material of object 2 without breaking bonds in the atomic lattices of this material and, therefore, without changing initial quality of polishing the surface layer, but with change of its initial optical properties. The modifier used is impurity additives, selected from a group which includes noble metals or boron, ions of which alter the complex refractive index of the modified layer.

EFFECT: design of an efficient method of marking precious stones.

5 cl, 1 ex,7 dwg