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Apparatus for examination, evaluation and classification of precious stones Apparatus (10) for examination, evaluation and classification of precious stones has an object table (11) on which a precious stone can be placed. The object table is enclosed in a housing (15) which is impervious to light. At least one light source (14) placed in the housing is adapted to project incident light onto the precious stone. A device is provided for turning and tilting the object table so as to vary the orientation of the precious stone relative the incident light. A digital camera (16) is placed in the housing, neighbouring a certain or each light source and adapted to record images of the precious stone, provided by reflection and/or refraction of the incident light. There is also a means of processing information for calibrating and analysing images, said means being programmed by a set of commands for colour calibration of images and subsequent analysis of the colour-corrected images by segmentation and constructing histograms. |
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Inside a diamond, in the region free from optically impermeable irregularities, an image is formed, which consists of a given number of optically permeable elements of micrometre or submicrometer size, which are clusters of N-V centres which fluoresce in exciting radiation, wherein formation of clusters of N-V centres is carried out by performing the following operations: treating the diamond with working optical radiation focused in the focal region lying in the region of the assumed region where the cluster of N-V centres is located, while feeding working ultrashort radiation pulses which enable to form a cluster of vacancies in said focal region and which provide integral fluence in said focal region lower than threshold fluence, where there is local conversion of the diamond to graphite or another non-diamond form of carbon; annealing at least said assumed regions where clusters of N-V centres are located, which provide in said regions drift of the formed vacancies and formation of N-V centres, grouped into clusters in the same regions as the clusters of vacancies; controlling the formed image elements based on detection of fluorescence of N-V centres by exposing at least regions where image elements are located to exciting optical radiation, which enables to excite N-V centres and form a digital and/or a three-dimensional model of the formed image. Images formed in diamond crystals from clusters of N-V centres are visible to the naked eye, by a magnifying glass and any optical or electronic microscope. |
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Method of detecting artificial colouring of diamonds Method involves recording optical density spectra of diamond crystals in the infrared range using a spectrometer. Absorption bands are determined after recording optical density spectra. Natural or artificial origin of colour is determined from the set and relative intensity of absorption bands in the 1360-7000 cm-1 range. |
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Method of determining value of precious stone Method of determining the position of at least one inclusion in a diamond involves providing material containing a chalcogenide of a group 16 element; raising temperature of the material to 100-400°C in order to achieve molten state; placing the diamond inside the material and establishing illumination wavelength used to illuminate the diamond so as ensure that the refraction index of the material is in the range of 0.1 times the refraction index of the diamond when the material and the diamond are in a defined temperature range. The diamond in the material is then illuminated and the illuminated diamond is then imaged to obtain images of the diamond and the position of at least one inclusion is determined based on the images of at least one inclusion in the diamond images. |
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Method of analysing cut precious stones Method involves recording optical density spectra of precious stones in the infrared range using a spectrometer fitted with a microscope working in reflection mode, performed as follows: the analysed cut precious stone or article with a precious stone is fixed in a holder with the platform up and perpendicular to the optical axis of microscope objective; the position of the sample is then chosen with focusing on the internal volume in the bottom part of pavilion such that the signal on the detector of the spectrometer is maximum, and spectrum of light passing through the sample and reflected from its surface is recorded. The background spectrum used can be the spectrum of the light reflected from a metallic mirror or spectrum of light reflected from the platform when focusing on the platform, or spectrum of light in transmission mode. The optical density spectrum from which the precious stone is analysed is calculated. |
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Method of identifying rough diamonds, cut diamonds and other precious stones Digital images of a precious stone are obtained when said stone is illuminated by a light source in the visible region and luminescent when the image is exposed to UV radiation. The obtained digital images undergo mathematical processing to obtain a graphical presentation of the distribution bar chart of pixels on the mutual relationship of components R, G and B, used to form the pixels, and a digital code based on coefficients of a polynomial which approximates the bar chart. |
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Method of identifying source of collection of diamond crystals Method involves exposing crystals to electromagnetic radiation in the infrared range, recording values of optical density of the crystals in the infrared range, calculating absorption coefficients of absorption systems or determining concentration of defects of the crystalline structure. After recording optical density values in an arbitrary direction, the position of the maximum of the absorption band is determined in the 1350-1390 cm-1 range. The obtained data are then statistically processed and compared with standard values of concentration of defects of the crystalline structure, absorption coefficients and the position of the maximum of the absorption band in the said range. |
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Method of localising diamond inclusions Diamond is put into a holder. The diamond is examined at a defined angle to obtain an image. A second measurement is taken in order to obtain two sets of data. The two sets of data are calculated on a computer. The said second set of data can be obtained by measuring depth or by changing viewing direction. |
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Method of embedding mark into diamond, obtained through chemical deposition Method of embedding trade marks or identification marks into monocrystalline diamond material, obtained through chemical gas-phase deposition, involves preparation of a diamond substrate and initial gas, dissociation of the initial gas, which provides the process of homoepitaxial growth of diamond, and to put trade marks or identification marks into synthetic diamond material at least one dopant chemical element selected from a group comprising nitrogen, boron and silicon is introduced into the synthesis process in a controlled manner in form of defect centres which upon excitation emit radiation with characteristic wavelength and in such concentration such that the trade mark or identification mark, under normal observation conditions, should not be easily seen or should not affect the perceived quality of the diamond material, but should be seen or become seen when illuminated with light with wavelength of the excited defect centres, the value of which is less than the said characteristic wavelength of radiation emitted by the defect centres, and visible under observation conditions where the said illumination is not visible to the observer. |
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Identification mark for marking valuables and method of making said mark 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. |
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Invention relates to devices which use ultraviolet radiation for testing objects, and is meant for sorting diamonds and, particularly for selecting diamonds from natural rough diamonds and cut diamonds with brown hue, where the selected diamonds are suitable for high-temperature processing at high pressure for decolouring, more specifically, type IIa and IIb, and IaB diamond crystals. A light-emitting diode with radiation peak in the wavelength range from 240 to 300 nm is used as the ultraviolet radiation source, and the detector of radiation transmitted through the tested diamond crystal is a photodiode. The electric signal from the photodiode is amplified with a converting amplifier. Intensity of radiation transmitted through the tested diamond crystal is indicated using a measuring device and in parallel using an indicator with operation threshold. The light-emitting diode is placed in a holder with a table. A narrow central hole is made in the table in order to pass radiation from the light-emitting diode. The tested diamond crystal is placed on the table, while completely covering this hole. The diametre of this hole is made smaller than typical dimensions of the tested diamond crystal. The photodiode is placed into the holder with possibility of changing its position relative the tested diamond crystal and possibility of fixing its vertical position, in line with the hole in the table, using a special detachable cover for the said table. |
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Personalised grown gem diamond Invention relates to artificail gem diamonds identifiable with a certain person or animal. A personalised gem diamond is grown from a charge that includes carbon being a product of carbonisation of the material provided by the customer, powder of spectroscopically pure graphite and a marker for which at least two elements are used that are selected from a lanthanide group and taken in a arbitrarily prescribed ratio to the extent between 0.01 to 10 mcg /g. |
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Method and system for laser marking precious stones, such as diamonds 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. |
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Laser machine for analysis, grading and marking-out of untreated diamond The machine has a laser scanning device, three-dimensional scanning system, matrix, masking device, electronic unit and a computer program for analysis of the diamond weight and characteristics of the brilliant or brilliants that can be obtained from an untreated diamond. |
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Device for observing information mark on face 7 of precious stone 6 is made in form of casing 1 for jewelry. Casing 1 for jewelry has substrate 2 to keep ring 5 with precious stone 6 on top of it and rotating cap 3. Rotating cap 3 has opening 15 in its top part; opening has 10x lens 16, that's why when cap 3 is open and turned by 30° angle, face of 7 of precious stone can be seen through lens 18. Moreover precious stone is illuminated by light that enters casing through slot formed when cap is opened. Light falls onto face slantwise and is regularly reflected through lens 16. Scope can be used for internal and external observation. |
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Evaluation of diamond's quality To determine if green-blue was subject ct to artificial irradiation or to ion bombardment, it is irradiated with light at wavelength of 633 nm for stimulation of luminescence emission, and luminescence is detected within range of 680 to 800 nm by using confocal microscope and spectrometer. Focal plane is canned in vertical along diamond. Quick reduction in luminescence accompanied with increase in depth points at natural illumination while even quicker reduction points at ion bombardment. Alternatively, to determine if diamond has to be natural/synthetic doublet, diamond is subject to irradiation at wavelength of 325 nm to stimulate emission of luminescence and luminescence is detected within 330-450 nm range. Sharp change in luminescence at increase of depth points at the fact that the diamond has to be natural/synthetic doublet. |
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Method for registration of absorption spectra of small luminescent specimens The absorption spectrum of small luminescent specimens is determined according to relation of intensities of light fluxes that have passed and not passed through the specimen, the luminescence of the standard specimen is used as the specimen through which the radiation flux has not passed, and the luminescence of the examined is used as the specimen through which the radiation flux has passed, and the absorption spectrum of the examined specimen is calculated according to the respective mathematical formula. |
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Method and device for testing precious stones Device comprises housing provided with solid body laser connected with the window in the heat insulating tank filled with liquid nitrogen and provided with the precious stone, semiconductor laser connected with the window, two spectrometers for detecting luminescence in the range of 550-10000 nm, and processor for processing signals from the spectrometers. |
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Method for estimating attractiveness of brilliant glow on basis of charm coefficient In the method, by experimental or calculation-theoretic way in glow images visible to observer optical characteristics of diamond glow are determined, including glow intensiveness, glow glimmer and color saturation of glow, characterized by level of decomposition of white color on rainbow colors, and also relief coefficient of glow, characterized by average number of intensive color spots in glow image, distinctive to human eye, and additionally, by dividing glow image on compound portions, average values of glow intensiveness of compound portions are measured. Optical characteristics of glow are transformed to glow factors. As average coefficient of brilliant glow charm, which is used to estimate brilliant glow charm, charm coefficient is used, calculated as average value of factors of intensiveness, glimmering, color saturation and glow image geometry. |
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Method of localization of inclusions in diamond Diamond is fixed onto holder and tested under specified angle for getting image. Then second measurement is made for getting two sets of data calculated by means of computer. The second set of data can be received by means of measurement of depth or due to changing direction of viewing. |
Another patent 2541850.