ALEXANDRIA, Va., June 9 -- United States Patent no. 12,650,388, issued on June 9, was assigned to Jubilee Diamond Instrument (S) Pte. Ltd. (Singapore).
"Gemstone testing device" was invented by Kui Lim Tam (Singapore) and Chuo Ann Ling (Central Link, Singapore).
According to the abstract* released by the U.S. Patent & Trademark Office: "The application provides an improved gemstone testing device for testing a gemstone specimen. The device includes a housing, a platform for supporting the gemstone, a first light source for illuminating the gemstone, a second light source for exciting the gemstone, a third light source for exciting the gemstone, a light filter, a sheet of light absorptive material for absorbing blue light ray, a camera mod...