US 12,228,521 B2
Surface analysis of gemstones
Tsung-Han Tsai, Maywood, NJ (US); Hiroshi Takahashi, Fort Lee, NJ (US); and Joey McEnery, New York, NY (US)
Assigned to Gemological Institute of America, Inc., Carlsbad, CA (US)
Filed by Gemological Institute of America, Inc., Carlsbad, CA (US)
Filed on Jan. 12, 2023, as Appl. No. 18/096,553.
Claims priority of provisional application 63/300,630, filed on Jan. 18, 2022.
Prior Publication US 2023/0228690 A1, Jul. 20, 2023
Int. Cl. G01N 21/87 (2006.01); G01N 21/88 (2006.01)
CPC G01N 21/87 (2013.01) [G01N 21/8851 (2013.01); G01N 2021/8864 (2013.01); G01N 2021/8887 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system for analyzing a gemstone using reflectance analysis, the system comprising:
a computer with a processor and memory in communication with a camera, a plurality of motors, and a light source,
the computer configured to cause the light source to illuminate a gemstone mounted on a rotatable stage;
the computer further configured to command the plurality of motors to adjust the camera such that a long focal axis of the camera is aligned with a normal of a target facet of the gemstone;
the camera configured to capture an image of the gemstone target facet using the camera and send the captured image to the computer;
the computer further configured to cause storage of the captured image and a correlated data set of information from the plurality of motors indicating an azimuth of the stage, slope angle of the camera to a horizontal, and distance of the camera to the gemstone;
the computer further configured to receive a first image of the target facet of the gemstone from the camera, detect a feature in the captured image of the target facet of the gemstone, map the feature in the captured image of the target facet of the gemstone, identify the feature in the captured image of the facet of the gemstone, and
determine a clarity grade or surface polish grade of the gemstone using all mapped and identified features on all facets of the gemstone.