Apparatus and method for fluorescence grading of gemstones

A system for analysis, the system comprising:

• a computer, in communication with an image capture system, the computer configured to receive a first color pixelated image, a second color pixelated image, and a third color pixelated image of a sample gemstone from the image capture system, the first color pixelated image captured under non-UV light and the second and third color pixelated images captured under UV light;
• the computer further configured to determine an outline mask of the sample gemstone using the first color pixelated image,
• wherein the outline mask excludes all background image outside of determined boundary lines of the sample gemstone in the first color pixelated image;
• the computer further configured to determine an apparent fluorescence area of the sample gemstone for the second color pixelated image and the third color pixelated image;
• the computer further configured to generate a fluorescence mask by overlaying the determined apparent fluorescence area on the outline mask and discarding any pixels in the apparent fluorescence area that are outside of the outline mask;
• the computer further configured to quantify individual color components in each pixel of the second and third color pixelated images within the fluorescence mask and convert values for individual color components to parameters representing a color characteristic of each pixel;
• the computer further configured to calculate a first fluorescence score based on an average value of parameters of all pixels in a defined area in the second and third color pixelated images within the corresponding fluorescence mask;
• the computer further configured to calculate a second fluorescence score based on all pixels within the corresponding fluorescence mask in the second and third color pixelated images;
• and
• the computer further configured to compare the first or second fluorescence scores to values of corresponding fluorescence scores of control gemstones with previously determined fluorescence characteristics to assess a fluorescence characteristic of the sample gemstone.