Gemmological Characteristic of the Northern Pearl of China

Hyriopsis cumingii is chosen as the pearly mussel. The gemmological characteristics of the northern pearl produced from Liaoning Province of China were investigated, with the help of hydrostatic weighing method, X-ray powder diffraction, Fourier transform infrared spectroscopy and scanning electron microscope. The testing results show that the relative density of the northern pearl of China is from 2.722 1-2.733 5. The mineral components of the northern pearl of China are aragonite and protein. The structure of the northern pearl of China is characterized as a form of “brick wall”. The thickness between aragonite layers of the northern pearl of China is 170 nm.