Systems and methods here may be used for automated alignment and focus adjustment for one or multiple sample gemstones on a stage, including determining gemstone sample tilt based on image data, automatically moving a stage to align the tilted sample, determining a focal plane that overlaps a focal point of a camera with the gemstone, and automatically moving a stage to the focal plane.

A multi-functional precious stone testing apparatus includes a portable housing and a testing unit. The portable housing includes a portable housing having a hand-held casing and a probe casing extended from a front end of the hand-held casing. The testing unit housed in the hand-held casing includes a UV light emission unit, a UV light reflecting and guiding unit, and a UV light receiving unit. The UV light emission unit produces and emits both a long-wave UV light and a short-wave light, so as to allow the UV receiving unit to sense the UV lights reflected and refracted by a testing object for determining various qualities and distinguishing types of diamond of the testing object.

A multi-functional precious stone testing apparatus includes a portable housing and a testing unit. The portable housing includes a portable housing having a hand-held casing and a probe casing extended from a front end of the hand-held casing. The testing unit housed in the hand-held casing includes a UV light emission unit, a UV light reflecting and guiding unit, and a UV light receiving unit. The UV light emission unit produces and emits both a long-wave UV light and a short-wave light, so as to allow the UV receiving unit to sense the UV lights reflected and refracted by a testing object for determining various qualities and distinguishing types of diamond of the testing object.

Methods, apparatus, and systems for managing optical characteristics of gemstones with diffractive structures are provided. In one aspect, a method includes obtaining a three-dimensional model of a gemstone including representations of surfaces of the gemstone, identifying a region on a surface of the gemstone having an optical value higher than one or more other regions on the surface of the gemstone by analyzing the three-dimensional model of the gemstone, and determining a diffractive structure to be arranged on the identified region of the surface of the gemstone, such that the gemstone with the diffractive structure has a higher optical performance than the gemstone without the diffractive structure. The method can also include fabricating the determined diffractive structure on the identified region of the surface of the gemstone.

A process of assigning a colour grade to a diamond, including the steps of (i) determining the N3 and C-center content of a diamond (110); (ii) comparing the N3 and C-center content of the diamond with a previously acquired data set from a plurality of diamonds each having a colour grading previously assigned thereto, and (iii) assigning a colour grade to the diamond upon a correlation of the N3 and C-center content of said diamond with a grade of said previously acquired data set; wherein said previously acquired data set comprises a correlation between N3 and C center content and optical absorbance in the visible light spectrum for each diamond of said plurality of diamonds.

A process of assigning a colour grade to a diamond, including the steps of (i) determining the N3 and C-center content of a diamond (110); (ii) comparing the N3 and C-center content of the diamond with a previously acquired data set from a plurality of diamonds each having a colour grading previously assigned thereto, and (iii) assigning a colour grade to the diamond upon a correlation of the N3 and C-center content of said diamond with a grade of said previously acquired data set; wherein said previously acquired data set comprises a correlation between N3 and C center content and optical absorbance in the visible light spectrum for each diamond of said plurality of diamonds.

Some examples herein include systems and methods of creating standards of gemstones of various classifications, which may display certain characteristics of the various classifications when excited by ultraviolet radiation and fluoresce in response. In some examples, a set of standards are created using fluorescent material, filters, and a radiation source to compare against a sample gemstone. In some examples, specific Light Emitting Diodes are selected to illuminate the gemstone samples under analysis.

Some examples herein include systems and methods of creating standards of gemstones of various classifications, which may display certain characteristics of the various classifications when excited by ultraviolet radiation and fluoresce in response. In some examples, a set of standards are created using fluorescent material, filters, and a radiation source to compare against a sample gemstone. In some examples, specific Light Emitting Diodes are selected to illuminate the gemstone samples under analysis.

A process operable using a computerized system (300) grades the clarity of a diamond (315, 400) as a function of internal defects within its body (315, 400). The computerized system (300) includes an optical image acquisition device (310), a processor module (320) and an output module (340) operably interconnected together. The process includes the steps of (i) acquiring via an optical image acquisition device (310) a plurality of top view images of a diamond (315, 400); (ii) in a processor module (320), detecting defects within the body of the diamond (315, 400); and (iii) from an output module (340), providing a signal indicative of the clarity grade assigned in (ii).

A process operable using a computerized system (300) grades the clarity of a diamond (315, 400) as a function of internal defects within its body (315, 400). The computerized system (300) includes an optical image acquisition device (310), a processor module (320) and an output module (340) operably interconnected together. The process includes the steps of (i) acquiring via an optical image acquisition device (310) a plurality of top view images of a diamond (315, 400); (ii) in a processor module (320), detecting defects within the body of the diamond (315, 400); and (iii) from an output module (340), providing a signal indicative of the clarity grade assigned in (ii).