After the pearls are selected for size, they enter the color selector machine. The principle of the color selector machine is to detect the surface reflectance spectrum of the pearls to determine the color. In this process, the pearls are placed under a light source, which emits light of a certain wavelength, and then the pearls reflect different spectra, thus judging the color according to the different spectra.#pearls #oysters #jewelry #pearllover #pearlgaga #fyp