Abstract: A method of color grading gems by a user by their inherent properties of shape, hue, tone and saturation. Each of the properties is variable over a practical range derived from a database. The database is created by digitally coding gem shapes, hues, tones and colors from digital photographs of gems of different, shapes, hues, tones and saturation. The variable properties are displayed on a screen and the user selects the best matching respective shape, hue, tone and saturation in comparison to the particular gem being graded. Upon receiving the user's selections, an image of the a gem having the shape, hue, tone and saturation selected by the user is displayed on the screen and translated into alpha-numeric code which can be communicated to any other user of the same system, enabling remote discussion and evaluation of the same target gem.

Abstract: A computer based expert system and method of grading gems by their inherent properties of shape and color, including hue-tone-saturation. Each of the properties is variable over a practical range derived from a data-base; the database prepared by digital methods from real gems. The grading is conducted interactively on-screen by visual comparison to the image of a real target gem, and the result, translated into alpha-numeric code, can be communicated by phone or via the Internet to any other user of the same system and database. The communicated code can be reconstructed by the system into an identical gem image, enabling remote discussion and evaluation of the same target gem, including matching and pairing of gems. A practical embodiment of the grading system and method is described, including application modes specifically aimed at gems and diamonds.

Abstract: A computer based expert system and method of grading gems by their inherent properties of shape and color, including hue-tone-saturation. Each of the properties is variable over a practical range derived from a data-base; the database prepared by digital methods from real gems.