A pearl grading method includes the following steps: (1) determining the color type of the pearl to be graded; (2) generating a simulated three-dimensional graph of the pearl to be graded; (3) calculating roundness, so as to obtain a roundness grade; (4) calculating the diameter of the simulated three-dimensional graph, so as to obtain a diameter grade; (5) drawing an illumination-wavelength reflection spectrum; (6) changing a detected part, and drawing an illumination-wavelength reflection spectrum again; (7) repeating the step (6) for at least two times; (8) performing weighted average to obtain a correction curve; and (9) comparing the correction curve with each glossiness grade spectrum baseline, so as to determine a glossiness grade according to the spectrum baseline with the highest coincidence degree. The method has the beneficial effects of low cost, high speed, good result consistency and high detection precision.

A pearl grading method includes the following steps: (1) determining the color type of the pearl to be graded; (2) generating a simulated three-dimensional graph of the pearl to be graded; (3) calculating roundness, so as to obtain a roundness grade; (4) calculating the diameter of the simulated three-dimensional graph, so as to obtain a diameter grade; (5) drawing an illumination-wavelength reflection spectrum; (6) changing a detected part, and drawing an illumination-wavelength reflection spectrum again; (7) repeating the step (6) for at least two times; (8) performing weighted average to obtain a correction curve; and (9) comparing the correction curve with each glossiness grade spectrum baseline, so as to determine a glossiness grade according to the spectrum baseline with the highest coincidence degree. The method has the beneficial effects of low cost, high speed, good result consistency and high detection precision.

A system (100) for viewing and ascertaining optical characteristics of gemstones, said system including a first and second integrating sphere (150,150a), wherein each integrating sphere (150,150a) is in optical communication with each other and having a spacer portion (116) disposed therebetween, a first light source (118) engaged with the first sphere (150) and for providing light to the interior of the first sphere (150) and a second light source (118a) engaged with the second sphere (150a) and for providing light to the interior of the second sphere (150a); at least one optical image acquisition device (110) in communication with the interior of one of the spheres for acquisition of an optical image of a gemstone disposed in a region between the spheres; a transparent platform (117) for supporting the gemstone between the two integrating spheres (150,150a); and a control module (120) in communication with the optical image acquisition device (110), for controlling the acquisition of optical images of gemstones thereof; wherein said optical image of the gemstone is processed by a processor to ascertain one or more optical characteristics of the gemstone.

Systems and methods here may be used for a setup of image capturing of a gemstone, such as a diamond, exposed to different light sources. Some examples utilize a setup that both sends light and captures the image through multiple dichroic beam splitters at pre-selected timing. The multiple light source and multiple dichroic beam splitter arrangement allows for multiple gemstones to be analyzed using multiple methods with minimal moving, changing, or adjusting the equipment for different samples.

A method generating a more accurate 3D model for at least two gemstones using external surface of the gemstones; storing, in memory, the more accurate 3D model of the first gemstone and the second gemstone; comparing the more accurate 3D model of the first gemstone and the more accurate 3D model of the second gemstone from the stored memory; calculating, based on the comparison, a matching score for the more accurate 3D model of the first gemstone and the more accurate 3D model of the second gemstone, the matching score being informative of a match between the first gemstone and the second gemstone; and identifying the first gemstone and the second gemstone as being the same gemstone when the matching score meets a predefined matching criterion.

A method generating a more accurate 3D model for at least two gemstones using external surface of the gemstones; storing, in memory, the more accurate 3D model of the first gemstone and the second gemstone; comparing the more accurate 3D model of the first gemstone and the more accurate 3D model of the second gemstone from the stored memory; calculating, based on the comparison, a matching score for the more accurate 3D model of the first gemstone and the more accurate 3D model of the second gemstone, the matching score being informative of a match between the first gemstone and the second gemstone; and identifying the first gemstone and the second gemstone as being the same gemstone when the matching score meets a predefined matching criterion.

There is provided a computerized system and method of generating a unique identification associated with a gemstone, usable for unique identification of the gemstone. The method comprises: obtaining one or more images of the gemstone, the one or more images captured at one or more viewing angles relative to the gemstone and to a light pattern, thus giving rise to a representative group of images; processing the representative group of images to generate a set of rotation-invariant values informative of rotational cross-correlation relationship characterizing the images in the representative group; and using the generated set of rotation-invariant values to generate a unique identification associated with the gemstone. The unique identification associated with the gemstone can be further compared with an independently generated unique identification associated with the gemstone in question, or with a class-indicative unique identification.

There is provided a computerized system and method of generating a unique identification associated with a gemstone, usable for unique identification of the gemstone. The method comprises: obtaining one or more images of the gemstone, the one or more images captured at one or more viewing angles relative to the gemstone and to a light pattern, thus giving rise to a representative group of images; processing the representative group of images to generate a set of rotation-invariant values informative of rotational cross-correlation relationship characterizing the images in the representative group; and using the generated set of rotation-invariant values to generate a unique identification associated with the gemstone. The unique identification associated with the gemstone can be further compared with an independently generated unique identification associated with the gemstone in question, or with a class-indicative unique identification.

A device for inspection and authentication of gemstones (diamond pieces) includes a first member having a plurality of gemstone receiving portions, a second member having a plurality of diamonds covering portions which correspond to the gemstone receiving portions; each of the diamond covering portions having a viewing and inspection opening formed therein, a connection member disposed between end portions of the first and second members, a seal placement area formed on each of the first and second members; and an authentication seal configured to be placed on the seal placement area. The authentication seal is provided on the seal placement area without obstructing the viewing and inspection openings. The size of the viewing and inspection openings is less than size of gemstones placed in the gemstone receiving portion. The viewing and inspection opening includes one or more elongated portions for inserting a twizzer therethrough for holding and rotating diamond.

A device for inspection and authentication of gemstones (diamond pieces) includes a first member having a plurality of gemstone receiving portions, a second member having a plurality of diamonds covering portions which correspond to the gemstone receiving portions; each of the diamond covering portions having a viewing and inspection opening formed therein, a connection member disposed between end portions of the first and second members, a seal placement area formed on each of the first and second members; and an authentication seal configured to be placed on the seal placement area. The authentication seal is provided on the seal placement area without obstructing the viewing and inspection openings. The size of the viewing and inspection openings is less than size of gemstones placed in the gemstone receiving portion. The viewing and inspection opening includes one or more elongated portions for inserting a twizzer therethrough for holding and rotating diamond.